Dear me, theres so much...
Make SURE you visit either of the free flight shows, it really is the highlight of the park in my opinion. There's a host of species that are nowhere else, or just at a VERY few places in europe... Note that Walsrode is one of the best when it comes to signage in the world, they move the animals around quite a lot, and i can't remember one species not being signed by them, they are very impressive when it comes to that.
Another point to consider is trying to contact them for a behind the scenes tour. Perhaps some people on here could help you with it, but it would make you see both the King and the twelve-wired BoP which are not on show. There were rumours that a king BoP was put on show recently, but that was also denied by someone who went shortly after, so chances are low.
I also want to state that if you pay attention during your visit there's not very much you can miss. All species are (as mentioned) signed, so you'd be able to spot them. The most notable species include;
- Harpy eagle
- Single-wattled Cassowary
- siberian, wattled and black-hooded (monchs?) crane
- asian and african open-billed stork
- sickle-billed vanga
- golden-headed quetzal
- Andean BEEP-of-the-rock

- horned parakeet
- sumatran trogon
- Kagu
- shoebilled stork
- Horned Guan
- australian and brown pelicans
- guano-and pied cormoran
- giant coua
- Arfak brush-turkey (free-ranging in the large dome, usually near the exit)
- too many ibis, lori, fruit dove, parrot and pheasant species to mention
The hardest to spot birds btw are in the free-flying part of the "Paradieshalle"(paradise-greenhouse). The main attraction here (for me) was the blue turako, which is one of the few animals i haven't seen yet on 2 visits...
My favorite of the zoo, and if I'm correctly informed then unmissable; the Montezuma Oropendola. Their sound is amazingly weird, and usually there's a large group in the huge free-flight aviary whose call echo through most of the park. When i visited in May they were not there, but according to visitors after me they are back. I think you missed the most impressive botanical moments of the year (the tulips in april/may and the rhodondendrons in may/june are TOP) but i bet you'll enjoy yourself immensely.
Make sure you post a report!
Oh and if you'd make a list, just search "Walsrode" on Zootierliste
