Driving:
Better understanding of how fast you're really going
In-Cockpit view
Far behind & up view (drifting)
Competitions:
Drifting
Dragracing
Ralllycross
Tuning:
Under-the-hood-view do-it-yourself tuning, not just 'press that turbo and install by pressing OK.
Being able to use both the NA tuning and turboing.
Aerodynamic kits.
Cars:
Alot more 80's-90's american and european cars.
Classic Opels.
More Volvos! How about a 2.4t 5cyl 4wd S60 to compete with the subarus?
Alot more Jags and Aston M's, both newer and older.
Brands:
SAAB
(9-3Viggen, 9-3ssAero, 9-3SportCombi 2.8t, 9-5aero & Griffin, 900Aero, 99Turbo, 93rally car, 92, Sonett -1,-2,-3)
Ferrari
(Enzo, F50, F40, F360, F430, F340, Dino, Testarossa, 550Maranello, 250GT, 512M, 575GTC, 612 Scaglietti)
Lamborghini
(Miura, Murcielago, Diablo, Gallardo, Espada, Countach)
Bugatti
(EB 18/4 Veyron, EB110, EB 18/3 Chiron)
Porsche
(911, 911turbo, 914, 924, 944, Carrera GT Prot., Cayman S, Boxter S, 997, 906, LMP2)
Koenigsegg
(CC85, CCR)
Maybach
(Exelero, 57, Zeppelin DS8)
And more minor brands..
Tuning companies:
AC Schnitzer
Startech
Brabus
Kleemann
Hamann
Other:
PS2>PC cable (photos/replays) and steering wheel+pedals comes with it :P