Don't really "hate" any teams. Certain players I can't stand and fanbases (for the most part). I guess, if I had to rate it around those criteria....
1.) Steelers - Not because they ended up with more points than us in the Superbowl, but because their players basically rubbed salt in the wound admitting many of the mistakes in that game favored them. Their fans, even with players of that team admitting the wrong calls were made, still won't admit they were gifted that game. However, the Seahawks did do quite a few things to give it away as well.
2.) 49ers - Don't care for their coach or most of the their fans. Would be sad to live down there and feel obligated to go their home games. When getting stabbed is likely a possibility from another fan of the same team you root for, you really need to question WTF is wrong with some people. They have a ton of talent on the team though. Novarro Bowman is an idiot as well. Respect most of the other players and I enjoy watching the games between them and the Hawks. Was close between the 9ers and Rams for this spot as I feel the Rams have enough talent to sneak past the Hawks and 9ers depending on injuries for both teams. Main reason I chose the 9ers is because I love life more when the Hawks crap on them. Beating the Rams feels just a little bit better than beating a non-divisional team.
3.) Redskins - Mainly because they feel RG3 is impeccable and head & shoulders above Wilson when in, IMO, they're on the same level overall. They're both very good at what they do and I doubt any Seahawk fans would trade Wilson for RG3 or vice versa for the Skins fans. Also, constantly seeing their fans post that we're over-rated, going to miss the playoffs and yada yada...it just gets redundant. You can only attempt to have an intelligent conversation with them for so long before you feel like you're getting dragged down by idiocy. It's like trying to have a conversation with a wall. One that has graffiti on it with spelling errors and a mural claiming Jim Jones is the GOAT at rap. Throw in a pig snout and little to no understanding of football aside from knowing a few common knowledge facts about a couple of their star players, and there you go. I know more about the Redskins players than 80-90% of their "fans".
4.) Bears - Jay Cutler & their fans. I do get a good kick out of laughing at Cutler throw more completions to the defense than his receivers.
5.) Chargers - No issues with the fans. I wouldn't mind punching Phillip Rivers in the throat though.