Focus RS has a GT25 Turbo and LSD as standard. It was a special/limited edition car and as such will eventually have the same cult status and no doubt residuals as the Escort RS Cosworth and Escort RS2000's etc before it. They can tune up to 300bhp easily and beyond if a GT28 Turbo is fitted.
TT's are really nice cars and in your price bracket too. My mate just got a 2001 denim blue 225 TT with leather and Bose for £11k recently. Same engine as Leon
Cupra R plus 4 wheel drive to harness the power. As others have also said, the S3 is worth looking at too - Same as TT mechanically but in 3 door hatch shell rather than the TT coupe shape and poorer dash.
Not sure what R32 you would get for £11k, but they are good cars too although the 3.2 V6 thirst would maybe be a put off.
Also, I wouldnt buy one myself, but the Alfa 147 with the big V6 engine is in that price bracket too.
Also in that price bracket are Vectra GSi's, Mondeo ST's, Honda Civic Type R's, Impreza WRX/STi's. Evo's, Clio 182's, Megane 225's, Celica 190's etc etc etc.