I too am will be int he market soon for some 6.5's in my new WRX. I had the References in my last car...if you hunt you can get them for 140 bucks or better, for the price they are quite good. Crystal clear upper mids (these speaks seem very well suited to female vocals). Personally i want something different though, because the tweeters sound very, very "bright" and have poor lower-mid/midbass. I was running 65w per channel RMS to them.
I have heard good things about a brand called CDT, not very common but reasonably priced. I also plan to look into Focal (expensive, i think!), Boston Acoustics...maybe Kicker.