I like NAnt but lately it has been giving me a few problems. Apparently the assembly it compiles just mysteriously fail to load in NUnit. Compiled via VS, they work fine. Anyway, it seems like I spend way too much time maintaining build files also. I think it may be time to look into msbuild again!

Update (12/31/2006):
Started looking at msbuild, seems like it will let me do the same as nant, with a bit less configuration work. Works for me!