First, it is vitally important that you game footage and your audio recording are of good quality. This means using the right codecs, rendering at the right resolution, recording at the right resolution, maintaining the proper aspect ratio, uploading the right type of file. This goes for SSLPs too, having them displayed in their native resolution, or upsizing to nearest neighbour. People will put up with you not having a pperfect voice, they won't put up with a shit quality video. I believe you mentioned you recorded commentary while you were sick? No. Don't do that you will sound terrible. Rerecord when you aren't sick.
As for the content, don't play blind. 99% of blind LPs are utter crap. Don't blind LP. Edit your footage. No one wants to see you die a bunch. No one wants to see you stuck. Cut that shit out. On a similar note, do practice runs before hand so you aren't wandering around the level, and you know where collectables, or ammo, or whatever are. As was mentioned you have to have good chemistry with your co commentators, and have a good sense of when to talk. Don't talk over each other ever. Don't talk over the whole video, specifically over cutscenes, but it is okay just to take a break and not talk. On the other hand don't have too much dead air, this is one of those things where this is no real guidelines for and is just something you have to get a feeling for.
Either informative or comedy on their own will work fine as long as they are at least interesting. A good set up for commentating with two people is to have one be very knowledgeable about the game, usually the person who is playing, and the other having a very limited knowledge. That will create a natural flow with explanations.
The game you choose isn't that important, as long as you are passionate about it in some way, either love, hate or something in between. If you aren't really that interested in the game it'll show and the videos will not be good. There have been amazing LPs made from some of the worst games ever made. The game being 'good' is irrelevant to the quality of your LP.
Something to remember is the above all else the LP is about the game. Not the person LPing the game. We don't care about your personal life, we don't care about your friends, it is not about you. The worst thing you can do is make an LP to try and gain some e-fame.
That's what I look for in an LP video. I would be happy to criticize your stuff once you start making test videos,