Agreed, Walken is one of my all-time favorite actors. It would be really tough for me to rank my favorite performances and roles of his, but I will point out that there is one role that I felt he was AMAZINGLY good in, but because the movie was sort of quirky and he wasn't the leading man, I don't know that man people look at this as one of his best.
I'm a huge fan of actors with great range, and "Blast from the Past" was a stellar example of just how versatile he is. You can look to some of his spots on SNL to see that he's got comedic chops, so it's not a complete surprise how good he was in this role, but I thoroughly enjoyed this movie in large part because of him and I think it's a fantastic contrast to some of the more serious characters he's played in some of his better known films.
Even if, like me, you find Brendan Fraser annoying, overrated, and in need of more cowbell, check out the movie for some other enjoyable performances, most notably Walken.