A lot of the times can be frustrating, but many times there's something to keep me playing. Out of my 3 characters I've given up on ret, love lock and was about to quit warrior until I got geared and learnt to play it properly.
Now my most favorite thing in PvP is using siegebreaker as a warrior and punting people off the map in the middle pathway of EotS. 600k HP lock? Smack! gone. Tanky ass DK grip me in? SMACK! gone. Holy pally in the back with all his CDs? Punt! later.
It's like hitting a home run, hole in one, and sudden death goal in overtime all in one.
Hitting people off the cliff in AB at LM comes a close second, but some classes can survive that.
Whats your favorites?