Sir, I posted this before Swagger's undeserved ban in Ubers. Ubers was about freedom, using whatever you want. Now it's overtaken by tyrants who think Shadow Tag is a broken ability (hint: it's not).
I have my own post I want to type but I want to address this first. Swagger was probably the most sensible thing to be banned in a long time. Being able to take down entire teams of cover legendaries with one pokemon is incredibly broken, forces almost every mon in your party to carry taunt out of fear of facing a player who instead of using logic and skill to overcome the opponent, would rather click the same 2 buttons over and over and wait for the rage quit. This was made worse by the same people actually leaving the game as soon as they are taunted or have their swagger mon killed. Also, ubers isn't just a banlist tier where anything should be allowed.
Anyway, my favourite tier by miles is doubles. The possibilities are (forgive the pun) doubled in this tier and it leads to, in my opinion, a far more diverse and enjoyable play environment. I've always found singles to be start, rocks, switch, defog, switch, rocks, switch and eventually a key member of your opponents team will faint, then you destroy the rest. This isn't an unfounded opinion, it may be outdated as I haven't played singles since may, but the length and level of boredom I got from playing singles made me stop. I used to hover around the top 100 in ubers and was somewhere on the middle of the ladder in OU, so I wasn't an experienced player, but I was by no means a noob.
I then moved to doubles and fell in love. The creativity, surprise and doubles prediction level made the game far more interesting, and I've been playing ever since.
The main problem with doubles, is the fine line between horrible gimmicks that embarrass the tier, and innovative sets that no one could ever see coming. An example of interesting sets and high level play can be seen in this game:
http://replay.pokemonshowdown.com/smogtours-smogondoubles-380
Teambuilding is another aspect of doubles I enjoy, as its far more complicated than building a singles team. Singles requires you to have reliable switch ins to thread to your team. In doubles, this is almost impossible as even if you can tank a hit you needed to, you still have to worry about what your opponents second mon will do. This brings me to the length of the games. I have a very small attention span, due to my ADHD, and singles games going on for 100+ turns in PP stalls are the definition of
oh god why for me. Doubles games on a bad day will last about 12-15 turns, sometimes more if the players are good but generally ladder games are short, meaning you have a far smaller margin for error.
My favourite part of doubles however, is that stall is almost non existent. Entry hazards are few and far between, and someone taking a turn to put up rocks or spikes up usually means their downfall due to the incredibly fast play style. The usual suspects in OU and ubers trying to stall in doubles is hilarious. Another notable thing is that swagger isn't banned in doubles. I am the biggest advocate of banning swagger in doubles, which was recently shot down hard in the doubles suspect thread :(
This is an example of why swagger/stall doesn't work in doubles (before anyone says anything, all the shit talking in the game chat is friendly, we're buddies from the PS doubles room we aren't actually arguing lol)
http://replay.pokemonshowdown.com/smogondoublesuu-171851738