This is a very interesting concept so I thought I'd try to do it myself. I have to say that ranking between hundreds of very good birds is a hard task but I tried. I will only consider species I've seen in my home country, namely Morocco.
Out of the 196 species I have seen to date in Morocco, this would be my top 20 of them today (though I'm pretty sure the list changes each day as it's a hard thing to make):
1 - Brown booby - (Sula leucogaster) - vagrant
Seawatching with one of the best birders in Morocco back in October 2020 (probably my best month birding by far), was a really fun experience as it was my first time seawatching and thus my first time seeing a lot of really cool species I dreamt of seeing (my first jaegers, scoters, phalaropes and my first shearwaters in Morocco etc...). The best of it all though, by far, was when my friend noticed a weird Sulidae species flying in the distance with a few Northern gannets that looked good for a Brown booby! Brown boobies are a very scarce species only occasionally seen during pelagics or seawatching in migration, proof being this would only be Morocco's 6th record of the species ever if accepted by the Moroccan rarities committee.
2 - Laughing gull - (Leucophaeus atricilla) - vagrant
When the 7th Laughing gull for Morocco was reported about 3h from my hometown in February 2020 while I was away in Spain, I deemed that my chances of seeing it were scarce as it would probably be gone by the time I came back. It was even more unlikely considering that nobody was willing to pick me up to go there which meant that a month after it was reported I still hadn't tried for it. The 8th of March, however, I decided that I would still try for it even if my chances were low because you never know what could happen first of all and also because Essaouira, where it was reported, has a lot more to it than just this vagrant. I first checked the river estuary by the entrance of the city where there were a lot of gulls but not the one I seeked for until moving to the city harbour, where it was originally reported: once again hundreds of gulls but not Laughing gull so I gave up on it. Low and behold, on my way back to the car, it was standing near some Yellow-legged gulls and gave perfect views!
3 - Common loon - (Gavia immer) - vagrant
My first ever successful (or at least countable) twitch! The 16th record for Morocco and once again I really thought my chances of getting were slim, even if I tried to twitch only one day after it was reported. A great bird which I could observer for some good minutes preening itself and diving, and obviously my first loon (as all loon species are vagrants in Morocco).
4 - Cream-coloured courser - (Cursorius cursor) - native
Probably one of my favourite species that I've seen if not my favourite (just down in the ranking because it's not a rare species compared to the four above). Just an absolutely amazingly beautiful bird that I've sadly only seen once (hoping to fix that this year!).
5 - Black-crowned tchagra - (Tchagra senegalus) - native
Another amazing species that I'm blessed to see rather often and which always gives great looks even if it can be hard to see at first.
6 - Red-necked nightjar - (Caprimulgus ruficollis) - native
Nightjars are just special birds so I was very happy to see my first one a few months ago. This one gave rather good views too, showing us how weird their flight is.
7 - Eurasian wryneck - (Jynx torquilla) - native
A species I've only seen twice (and the same year at that) but what a species! Definitely one of the most unique I've ever seen.
8 - Fulvous babbler - (Argya fulva) - native
A very vocal species that is nearly always in small groups. I just love the way they jump on the ground. Our only species of laughingthrush too, which is a fantastic family of birds.
9 - Great spotted cuckoo - (Clamator glandarius) - native
A colorful species and one of the few where the juveniles look, in my opinion, much better than the adults. As with all cuckoos, their brood parasitism behaviour is also very intriguing.
10 - Rufous-tailed scrub-robin - (Cercotrichas galactotes) - native
Another really nice looking passerine, especially the males and their reddish tails that they flick often. One of the species that mark the arrival of spring as well.
11 - Maghreb magpie - (Pica mauretanica) - native
One of the most common species here but also one of my favourite, these very active birds differ from their European counterparts notably by their patch of blue skin behind their eyes, which adds a nice touch of colour to an already great genus.
12 - Moussier's redstart - (Phoenicurus moussieri) - native
The males of this species are simply some of the smartest birds there are. The females are really cute too! I'm always happy to see this common species in any case.
13 - Eleonora's falcon - (Falco eleonorae) - native
A species I've seen a few times now and by far my favourite species of falcon I've seen. Rather rare, gorgeous (especially the all dark form), mostly found in one of my favourite cities (Essaouira), it ticks all the boxes.
14 - Bonelli's eagle - (Aquila fasciata) - native
A really large raptor which I see quite often at my local spot. They're nearly always in flight and as such taking pictures of them is tricky but they sometimes can give great view:
15 - Northern bald ibis - (Geronticus eremita) - rare native
Northern bald ibises, unlike what people may think, are super easy to see if in the right place. Nonetheless, it is always a pleasure to see these peculiar animals, especially knowing that Morocco has played a huge part in their conservation.
16 - Red crossbill - Loxia curvirostra - native
A mountain endemic (except in winter sometimes where in irruption years they get to the lowlands to find food), I've only seen this species once, about three weeks ago actually. A really nice species of which the local taxon (ssp. poliogyna) might be split in the near future.
17 - Black stork - Ciconia nigra - native
An unexpected find while birding at Tamri one day, a few juvenile black storks were one of my best finds in 2018. A really nice species that is quite hard to see in Morocco, especially where I live.
18 - Marbled teal - Marmaronetta anguirostris - native
For a very, very long time, my nemesis species: I tried to see this globally rare duck (but actually quite common in Morocco) for four years, to no avail until I got mediocre views, twice, of some of them in July and August 2020.
19 - House bunting - Emberiza sahari - native
This species could honestly be much higher on my ranking seeing how much I love them. They're the epitome of cuteness in Moroccan birding and make great sounds. I'm really happy to see them nearly daily.
20 - West African crested tern - Thalasseus albididorsalis - native
This place could've honestly gone to many other species but I finally decided to choose this one. Terns are some of my favourite birds and one of my favourite species of terns is this one: a recent split of Royal tern, they're the second largest tern in Morocco behind Caspian and are also one of the harder ones to see, so I was happy to see one of them at my local spot last year!
Honorable mention (yes I'm cheating a little):
# - Steppe grey shrike - (Lanius excubitor pallidirostris) - vagrant
My only true rare find to this day, I noticed a really pale and unusual great grey shrike while birding at my local spot last October which I thought could've been something interesting (Steppe grey shrike did come to my mind but I always try to measure my expectations when I see something weird) and indeed, according to some of the best birders in the country, it does look like one! I have now sent a report to the Moroccan rare bird committee about this bird, which would become the first record for the country ever if accepted (though chances of it being accepted are honestly not so high). This isn't in my ranking however because as of now, it's only a subspecies and also because I didn't get sheer excitement from it on the field, not knowing what it is until I analyzed pictures (and also because it might end up being rejected by the rarities committee anyway).
As for the species I want to see most here, this is once again a really really difficult task, but I came up with this top 15 nonetheless:
1 - Marsh owl
2 - Houbara bustard
3 - Golden nightjar
4 - Greater hoopoe-lark
5 - Little crake (a crake species in general)
6 - Andalusian buttonquail
7 - Sudan golden sparrow
8 - Namaqua dove
9 - Lichtenstein's sandgrouse (a sandgrouse species in general)
10 - Levaillant's woodpecker
11 - Blue-cheeked bee-eater
12 - Bearded vulture
13 - Double-spurred francolin
14 - Desert warbler
15 - Streaked scrub-warbler
