How to become a successful YouTube game commentator?

I want to be a gaming commentator on YouTube much like TheSyndicateProject and Ali A. I know I won't become THAT great but I want to know what people would like to see and what it takes to get views. And do you have to be great at the game to be one? For example I'm pretty good at zombies but obviously not nearly as good as Syndicate, would people still watch even though I'd only get to like round 45?

The reason why YouTube channels are popular are because of either a) They build on something that has a huge fan base, like (unfortunately) Minecraft or b) They're unique (which is very hard to try and be) like HowToBasic. You need to be somewhat likable, have a voice that doesn't get dreary after a few minutes and you need to be confident. Also a good personality wouldn't be too bad. A good sense of humor is critical, as without it, your videos are going to be boring unless all you plan on doing are tutorials.

Try and do a joint channel as well, it helps to create a unique feeling to your channel and always try something which isn't your run of the mill video. Even though the Yogscast and KSI and the Syndicate Project all do basically the same videos every time nowaday, they got to their current position because they were something that was outside of the box.