I casually game online in most of the games I play, but I've always preferred solo gaming. Playing with friends is fine and can be quite fun, but if you're forced to play random people, that's just laborious torture. I don't have any special equipment beyond a controller, and I've stopped using a headset because I don't want to talk to random people who do nothing but scream garbage down their headset, so just a controller and me. I'd say I'm average-ish at most games online, because I don't have the time I used to have to dedicate to gaming, and so coming up against those who do...it's not a pretty sight ;).
I love online gaming. An increased social interaction makes the game I'm playing more fun, exciting and engaging. Either, you'll enter combat with other players or work together to achieve an objective and this creates a level of excitement for the game.