And oh, I just remembered about My Death Flags Show No Sign of Ending. Like I mentioned earlier, not his game character, but an NPC he takes over. Still a good read nonetheless. And regarding the other recommendations, although I like a good portion of them, some might not fit your requirements. Like Skeleton Knight in Another World. Although I like it, he is kinda beta-ish, but it isn't a bad read nonetheless.
Ahh, I see. Do try to make one list now. It always helps people trying to give you recommendations! Either way, from your description, you're probably going to enjoy My Death Flags. If you like non-human protagonists, Kumo Desu ga, Nani ka? is a must read, though it's not set in a game world, necessarily.
No one mention this : http://royalroadl.com/fiction/3598 ? Title : polymath redux Synopsis : very op mc transported to another world with his game character, he cause a chaos there with his clone...
Was dropped by original author , picked up by current author who is still in school so updates will be very rare for the time being.