Here are my top 10 - though I may edit at a later date (assuming I get to keep the SRT6 too - )

1967 Shelby Cobra 427 (original) (Royal Blue w/White stripes and Black interior)
2005 Ford GT (Quick Silver Metallic (no stripes) w/Black interior)
1959 Cadillac Convertible (Red w/White interior)
1955 Mercedes 300SL Gullwing (Red w/Brown interior)
1989 Porsche 959 (White w/Black interior)
1935 Auburn Boattail Speedster (Red/Black 2 tone w/Black interior)
1948 Tucker (Color doesn't matter)
1933 Packard Convertible (Black w/White top and interior)
1932 Ford Hiboy (Black w/White top, no fenders, etc.)
1949 Mercury Coupe (chopped, flamed, lowered, etc.) (Black w/Black interior)