Same as on youtube videos; you can like/dislike. This is self explanatory. And an Edit/delete oneself's own post would be good as well for such times when you double post the same message by accident or when you wish to add more to your post.
A thanking feature could be interesting, but like/dislike seems to be like a ripoff from Facebook. The thanking system could also bring a mods attention to a merit worthy comment on a game.
AG pretty much works on merits though. Good posts are rewarded with a merit. I do admit though, that Im often curious about what others think about my posts. I usually go to the rate the above users... threads, but I think a thanks or reputation system would be nice.
I could see the like/dislike button working for something like game reviews, or even for liking merit worthy comments. But I would not apply it to member profiles, where you can give members a positive or negative rating.
Changing ratings could be fun XD we could start a forum movement where everyone ranks Sonny 0.5/10 for a day and see how far it drops XD
Anyways there's not much more I can add here... I'm for all the ideas, except like/dislike doesn't really make sense. Wouldn't dislike be if someone has a really negative review on something you love? What would that actually show. I think that the vote up thing needs to be brought back instead of like/dislike. I enjoyed finding comments that were way too big XD
Well, decisions being affected by one's opinion always happens. I suggest people's votes have their own weight according to several factors. Or maybe just revive vote up.
What about some group of people (like moderators, only more people with less power) that are manually picked by the moderators that if they like/dislike someones post, they can give/take one AP from the poster. They also have to shortly explain to each poster they liked/disliked their post, so that there would be no problems with the "critics"