Those two are OK, I guess, but they're far from my favourite. Especially when it comes to video games. Instead, that honour is shared between two accounts. Two very different accounts.
I like them both because they epitomise the very best of what the service has to offer, at least to me: serving as a worldwide soapbox for jokes and information. I don't give a stuff what someone had for lunch, or why you're joining millions of other people making the same jokes about E3/the NBA/Mad Men. I do, however, like this stuff.
The first belongs to Al Swearengen of the Gem Saloon, who after hanging up his chamberpot and shot glasses has got himself a job as a creative director in the video game business. His daily exploits are...frustrating.
The second is id's John Carmack, who at first glance makes it look like his Twitter account is being run by a machine. Until you realise it's actually being written by Carmack, and that instead of filling the service with what he hopes will make other people think he's cool, he just opens his head and dumps whatever he's actually thinking about. Which is mostly completely random code or tech talk.