B.R.
In my opinion, changing jobs won't really help. In every job, you will find annoying, difficult people. Every work place has a "suck-up". You can't control other people, but you can control your reaction to them.
My advice: ignore the suck-ups. They will eventually get what's coming to them.
As for people pushing work off onto you, here's what you do: First, clarify your job responsibilites with your boss. Say you are only responsible for doing job A. When annoying co-worker asks or trys to make you do job B, simply don't do it. When it doesn't get done, the boss will find out that your co-worker is a slacker. Bosses don't want to look bad to their bosses, so he or she will want to address the problem with your co-worker not doing his or her assigned task. By doing your co-worker's job for them, you're letting them off the hook and giving them a free ride.
Please hang in there... things will get better.