In order(If I wasn't concerned with gas mileage, insurance or inclement weather):
Any unmodified 1987-1993 5.0L "notch" mustang LX 5 speed
1986-87 Grand National or GNX (if you can find one for 15k)
1996-2001 SS Camaro 6 speed
1996 Impala SS (love the Console shifter in the 1996 model)
GMC Syclone or Typhoon (good luck there just finding one)
used SRT-4 Stage II
Find a good, low mileage 1991-1994 SE-R Sentra, get the SR20DET motor and go nuts with hi-po parts with the rest of the money
And, for Us New Englanders,a WRX Impreza...gotta have the AWD

Just my .02 cents