The thing that I always loved about TF2 was you would build comradery over the course of several games. This was made possible by the easy favoriting system, usable chat, and the teams that stayed consistent from game to game. Uber admitted the chat sucks, and are looking to fix it. The official servers tend to have the best ping, so I'm not going to be favoriting anything but possibly a clan server or a server with odd settings(sumo servers, highlander servers, extended games). The only thing that's missing for me is the server option to retain teams between games. So long as auto-balance is enabled the teams should stay fairly even. This should be an OPTION, not the default, the default is great for pubbing on random servers. THAT SAID, pubbing on choice servers(modded settings, clan servers, other) is very community based. Keeping teams consistent on a game-to-game basis builds community faster. If I end up on the same team as someone else repeatedly or against someone, I get to know them faster(and either love or hate them respectively). Rivalries and friendships are fun.
