Yeah, I'm sure vast numbers of people will disagree with me on this one, and that's okay. I've just come to the realization in the last week that I find Battlegrounds much, much more enjoyable than Arena. I'm not saying that Battlegrounds are harder or demand better skill, I'm just saying for my personality type they're more enjoyable.
Generally speaking I'm not a competitive person. I'm not playing WoW to try and prove something, I don't think I need to be the best at what I do. However, when I'm part of a 'team' I can get fairly competative. Now, before I go any further, Arena doesn't feel much like a 'team' activity to me. Feels more like a glorified duel, which is something I don't particularly enjoy. Battlegrounds though, feel much more like a team sport to me. I think that, in large part, it's the presence of goals and objectives that change the feel for me. It's not just about beat the poop out of the other team before the beat the poop out of you.
As a rogue in PvP, I'm an opportunist. I don't run into the thick of things and try and beat someone down, I prefer to remain on the outskirts of combat, in stealth, waiting for an opportunity. I don't pursue the warrior/priest pair that's heading for my tower, I keep my eyes open for the lone shaman or druid who I can easily dispatch when caught unawares. That may not be 'fair' from other classes perspectives, but I figure that's what rogues are made for.
edit: I started this post last friday and promptly lost my train of thought, I'm trying to pick it up here and at least finish it, but no problems on coherency.
Battlegrounds, as opposed to Arena's, seem to reward this style of play. It's very possible for a rogue to remain hidden for a while and strike at the most opportune moment. I like the idea of a few rogues sneaking behind enemy lines and quickly turning the tide of a battle. I love sneaking over to the Farm in AB, swifly eliminating the opposition and capping the flag. That's what PvP should be. Good PvP requires a certain amount of fear of the unknown. Rogues, and druids to a lesser extent, are that unknown. Arena, being a closed environment by design, prevents this.