I always recommend 4 to start with. Great season. 4 and 5 are my favorite seasons, but 5 dives right in, so I say start with 4.
I am a 24 freak! BTW, my cell phone ring is the do do. . dooo do that the CTU phones make
I am sooo excited for season 6 because they have the opportunity to not "save L.A." if you know what I mean. I wont say anything else in case everyone hasnt seen it. 6 has the potential to be really effin cool!
Jack Bauer FTMFW!!!!
EDIT: BTW, if you havent seen season 5 and cant wait for the DVDs its available on iTunes.