I'll second Log Horizon. Part of why the world feels more thought out is because Log Horizon's author was a high level player in a guild of high level players, playing Everquest 2.
On the other hand, SAO's author was a Ragnarok Online scrub in awe of RO high level players who're like gods to scrubs, which influenced how he wrote Kirito.
Also Log Horizon's author has one "problem": he ends up making lots of interesting characters and then shifts the focus on them, and off the main cast. This isn't entirely a bad thing though.