Here's the rundown of all the models I've ever owned... A lot of these I've had since I was a kid, and a lot of these have been sold, which will be denoted with asterisks.
Minichamps:
Opel Astra DTM (ATS Wheels, Stefano Modena)
BMW M3 GTR (#42 ALMS Lehto/Muller)
McLaren MP4-6 (Senna, of course!)
Williams FW19 (Villeneuve, limited edition box)
Maisto:
Mercedes Benz CLK-GTR (#11, D2Privat )
Mercedes Benz CLK-DTM (2001 version, #2, Peter Dumbreck)
Mercedes Benz CLK-DTM (2002 version, #9 Jean Alesi)
Audi R8 (2001 Le Mans Winner, #1)
BMW V12 LMR (1999 Le Mans Winner, #15)
Porsche 911 GT1 (1998 Le Mans Winner, #26)
Honda S2000
Opel Speedster*
Ferrari F50 (yeah, yeah, I know...)
Porsche 911 Cabrio (993)*
Porsche Carrera GT
Kyosho:
Lancia Delta HF (1992 Tour de Corse, Auriol)
Lancia Stratos (1975 Monte Carlo Rally)
Lamborghini Countach LP500S*
Hot Wheels:
Lamborghini Murcielago*
Ferrari 333SP
Dodge Viper GTS-R
Honda Civic Si (St00pid Street edition, I only kept it because it's getting rarer in red...)
63' Pro-Stock Corvette
UT:
McLaren F1 LM (Orange road version, uber rare, but I broke the rear wing off...
)
Porsche 911 Turbo (993)
Porsche 911 GT1 (Road version)
BMW 325i (#6, Winkelhock)*
Audi A4 BTCC (#5, Pirro)*
1997 Reynard/Mercedes Champ Car (Greg Moore, seen around 250+$ on Ebay, this one's a keeper!)
BMW M3 (E36, yellow)
Alfa Romeo 155 DTM*
AutoArt (this is the big one... enjoy!)
Nissan Skyline GT-R (Purple)*
Nissan Skyline GT-R (Gran Turismo Edition)
Porsche 917K (1971 Sebring Winner, #3 Martini/Rossi)
Subaru Impreza WRC (1999, Monte Carlo Rally, Burns)
Subaru Impreza WRC (2001, Portugal Rally, Solberg)
Subaru Impreza WRC (2002, Monte Carlo Rally, Makinen)
Peugeot 206 WRC (2002, Tour De Corse, Panizzi)
Ford Focus WRC (2001, Monte Carlo Rally, McRae)
Toyota Corolla WRC (1998, Rally GB, Auriol)
Toyota GT-One TS020 (1998, #27)
Toyota GT-One TS020 (1999, #2)
Lamborghini Diablo GTR (black)
Porsche 911 GT3R (white)
Chevrolet Corvette C5R (1999, #2)
Callaway C12 (Silver)*
Lamborghini Miura SV (Red)
Dodge Viper GTS-R (#51, 1998 GT2 runner up)
Mazda RX8 (titanium)
Mini Cooper S (Optional equipment version)
Mitsubishi Lancer EVO VI WRC (1999 Monte Carlo Rally, #1 Makinen)
Mitsubishi Lancer EVO VII WRC (2001 Rally GB, #7 Makinen)
Panoz Esperante GTR-1 (1998 #4)
Mitsubishi Lancer EVO VII (road version)*
Subaru Impreza 22B STi
BMW Z8*
Lamborghini Gallardo (Black)
Bburago:
Dodge Viper RT/10*
Dodge Viper GTS*
Ferrari F40*
I think that's it...
Had a bunch of 1:43s, too, but I sold them all.