WWTBAM - definitely worth trying at least once each trip! Don't go thinking you are going to get in the hot seat, maybe you will get lucky, but just fun to see if you are able to answer the questions. It is also a nice break to sit and relax for a while between thrill rides like TOT and RnRrC.
Wildlife Express - we didn't always do this, but we actually liked doing it after we gave it a chance! The train ride itself is just a view of some of the behind the scenes spots, but the destination is fun too. There is a small petting "zoo" with farm animals, generally we have seen a character inside the building there (Pocahantas and Rafiki for example), we also have heard a talk about ferrets with a live ferret. This is not necessarily a "thrill" type attraction, but it is a nice, relaxing stop. With kids we do the little booklet that has stations where you learn something and then get a stamp, so going to Conservation Station is a must. The CMs that we have encountered at these stations have been some of the nicest, funniest CMs we have encountered! In Dec, the two young men working at the stop on the way to Conservation Station were so fun, I'm glad we didn't miss it!
I look at both of these as not the most "thrilling" attractions, but I continue to enjoy them, and would miss them if we skipped them!