Where can I find free downloadable games?

I’m referring to games like Battle for Wesnoth. Fun, extensive games that last for a long time, are plot driven, and have decent replay value.

I want them to be downloadable, since online games tend to have limits such as monthly bandwidth.

I absolutely do not want “free trials”, just plain free gaming.

I know of a few sites, but I figured getting some more to add to my list would be worth 5 points.