I’ve been in and/or ran my share of games over the years. Some were really fun, others ended in some drama lol Such is the nature of rpgs. Sepphara, would love to get back into gaming sometime, but I’m afraid I don’t have the time (toyed around with a loose form of role play at formspring, and don’t even go there anymore, ugh). Good luck to you 
Queen, part of the prob you had imho, was the type of game it was. If I remember right, the rules of the game you were in was there was no rules, and no GM guiding the story. That type of gaming doesn’t work for everyone and seems to be in my experience, far more prone to cliques and drama. Even a game of tag has ground rules to try to ensure fair play lol
I personally like direction and limits on characters (canons or OCs - games that have pre-approval of characters help prevent uber characters and power playing - not to mention make sure well thought out characters can enter the game -although you can get god-modding in those games lol sometimes you can’t win so yeah it does for me largely depend on who is gm-img too).
Rules also help if things are in place like you can’t just up and say what damage your attack does to another’s character etc so that can prevent the ganging up effect that it sounds like you experienced. control over your character and his/her destiny is pretty important to most people, but the opposite can suck too - there’s always the people that no matter what happens or what attacks their sue is faced with, they never get hurt etc and that’s no fun either :-p So yeah it’s ideal if the people coming together to game have the entire interest in the story in mind, not just focused on their own beloved character. asking people to be fair and reasonable is sometimes a taller order than it should be though!
seems like people have different gaming backgrounds though, and each rpg is a little different than the last. depending on how you like to game, your enjoyment of the game may vary. i would say if you want to consider trying gaming again and sepphara sets up a game, observe for a while. See how its ran and determine if its style is a good fit for you. who knows, in a different type of game, you may have an entirely different experience.
For me, if it’s not recognizable as Thundercats then it’s more like original fic with thundercats-like characters. I like some rules, including that the canons should behave in-character (and that canons need to be in it - personally I don’t care for games that are entirely people’s OCs), and a gm guiding the story’s direction, but that’s just me
Although I was in a bizarro rpg that was a blast - all the canons were OOC on purpose but it was hilarious - not bad if that’s what you know you’re in for when you join LOL
on the flip side, I was in a different rpg where one of the canons was unrecognizable in every way…so hard to game reactions to that lol the only thing familiar about it was the characters name and no, there was no reason for the behavior, it’s just how this person re-imagined this canon character. It just should have been an OC shrug