I voted Forum, because it's the most important feature for long-term HG support of a particular game. If the forums are dead, it's a good sign people aren't interested in a game. But a thriving versatile forum encourages people to contribute and to ask questions, and it's this sharing of ideas that maintains a community and supports a game.
I don't care so much about seeing colors and all that, but it would be really handy if the forum had a PM box where you could send someone messages without cluttering up the board or having to post your personal email address on a public forum. Of course it would be kinda cool to post in different colors, change the color palette of the boards, maybe even have avatars. But I'm thinking of something useful that I miss from other boards.
Downloads/mods/scenarios: I'd like to see the downloads and scenarios section integrated into the forum, so that comments and information about the scenarios and downloads is searchable via the forum search function. I might be looking for a specific thing a modder has said about his mod, but can't find it because it's in one of the comments posted in his review for the download. Very frustrating.
Crunkatog on ESO
Bart331 balance suggestion: aztec: remove civ
Voltiguer: Ender, Sioux in 1.04 will be a top civ, no matter how many layers of Sioux goggles you put on
schildpad on Elephants: ...their mansabdar unit sucks so hard it looks like a black hole
Crunkatog on Steam.