I plugged this show on the Official Lost Thread - got really into it during the mid season hiatus of Lost!
I now probably rate Heroes over Lost as I feel that the show has a definite story arc whereas Lost is plain and simply dragging it's heels whilst they think of one! (I'll still watch both though!).
Another great show that I think everyone should watch is '
Dexter'. It's on Showtime in the US and the first season has already finished airing. It's a pay channel so the show seasons are short at 12 episodes usually - but well worth watching!
Cheers,
Andy