Sherlock Holmes never fails to make me feel like a little kid again. (Not so much the new movie, but all the old productions and especially reading the books/sections of the books.)
The Hound of the Baskervilles = still the best one. (Which, I suspect, is an opinion on par with 'I think breathing is important for people' or 'man, water really hydrates'.)
This post has no point. It's just random nostalgia.