first of all your not gonna get a "fast" car for 10k, wrx's arent fast, they are quick but definatly not fast.
these are what id pick...
wrx for obvious reasons, super underpowered engine untill the turbo spools, keep in mind, if you wanna have quick acceleration in a wrx, your gonna have to be really close to redline all the time. and its gonna kill your gas mileage. definatly a great car, and can take a hell of a beating and they handle great.
just remember, just cause its a wrx, doesnt mean its a rally car, first of all and most important, rally cars have extremely nice roll cages, you roll a rally car, you keep going, or if your upside down you walk away without a scratch. you roll a normal very badly you have a very good chance of dying. im not saying drive like a pussy, just find a big parking lot or something if you wanna drift around.
next, a newer legacy gt. i think its 2004+ they are faster than a wrx, and much nicer and more baller, better powerband, and just as easy to mod. might be a little expensive though.
1.8t a4, drives much better than a subaru, with the same performance you would get from a wrx or legacy gt.
and my favorite.... bmw e30 325ix, they were made from i think 88 to 91 or something. as reliable as a subaru, and built much tougher. honestly id say it seems faster than a wrx, it dosent have the numbers to back it up, but keep in mind its 1/4 mile and 0-60 times are from 20 years ago when tire technology wasnt even half as good as it is today. so much more off the line spinning.
but anyway, its a 6cyl so its got a great powerband, chip it, put in a full exhaist, a couple other small mods and you will be beating stock wrx's. its got the ground clearance of a small suv, and handles better than an sti could ever wish. you would be amazed at how great of a car it is, its just built perfect in every way. almost all bmw entusiasts will tell you that the e30 3 series was the best 3 series bmw has ever built BY FAR. you can pick up one for 4 grand, 6 or 7 grand in amazing condition. put the rest of the money into the engine, tires, suspension, etc...