Oh, I totally hear you! Personally I find aggro decks annoying to play against and not a huge fan of playing them myself, though sometimes it's just what seems necessary with nothing else is working for me.

Arena's are fun and I play them here and there. I only do so-so in there, usually between 4-6 wins...though I did manage a 12 win a long while back. Even though most tier lists have mage ranked 4th or 5th, they still tend to work the best for me. The others I tend to take in order are rogue, hunter, priest, paladin. Most guides have warlocks as a top tier because of the card draw, but I've just not seemed to get good card options when building my decks.

For a while it's seemed like choosing cards that add to ones on the board tend to do well (like +1/+1, adapts, etc,) especially when mixed with some direct damage and removal cards. So much depends on the 'luck of the draw' when making the decks as well as figuring out how to play them well.