...and speaking of teams to hate.
I guess if I had to list mine, they would be (not necessarily in any order):
-Rams - Division rivalry going back forever. Shoudl be self-explanatory.
-Seahawks - Other division rival. Plus Holmgren. So, yeah.
-Giants - Probably the 49ers' most significant and longstanding rival outside their division. Plus, the last NFC championship game that they did not deserve. Plus Eli. Yeah...hate 'em.
-Cowboys - Not gonna waste keystrokes.
-Patriots - Probably just a temporary dislike, but I can't stand BB or Brady (although I'm starting to warm up a bit to Brady). They committed the unforgivable sin of keeping Peyton's Colts out of the Superbowl several times.
Interestingly, the Cards are not on that list. Even though they've been a division rival forever as well, they've never really done anything to garner any dislike, and they have a habit of having pretty likeable players. I pretty much only hate 'em for 2 games a year.