Stupid ass washing machine...
Don't know what you mean, OP. The Reach forum gets panned constantly on this site, and for good reason - it's a crazy noobfest over there, and your chances of reading a good thread are damn near impossible.
The Flood, to me, feels like a home on this forum. Once you get past the Bronies (sorry guys, just personal preference. I'm sure MLP is wonderful in your eyes), idiots, wrong-forum-posters and John Cena, there's generally a lot of interesting discussion and I actually think a lot of what I read and post on The Flood has helped me a lot when discussing issues in real life. God knows you learn how to form an argument pretty darn quickly... or else.
The Universe pre-Halo: CEA and Halo 4 was also a great place, and largely still is. Pity it's so quiet though (not as quiet as The Classfieds! Tee-hee-hee!)