My favorites for cheap boards are Olimex (http://run.to/pcb) and Myro (http://myropcb.com). Not the fastest approach, but you get full mask and silk and they both let you tile whatever you want (including repeated patterns) in your board area for the same price - that can save big for small prototype boards.
One note of caution, I've only used myro once and they failed to fill in a silk polygon (it drew a thin border instead). I didn't have any copper polygons so I don't know if that could be a problem or not, but I did get the free gold plating (no kidding). Otherwise their quality was excellent. harry
