These are all from RugsUSA.com and, unless I slipped up, should all be available in large sizes for under $400.
-colorful but not too jarring
-multicolored for fun and stain-hiding, but not too busy
-potential for unisex room
This is the look I gravitate toward. There are also lots of options for more contemporary looks with solid colors or clean geometric patterns, which are not bad. I like these top three a lot, but I also think the faux-traditiona look could work well and be versatile.