Depends on how big you want but a good 323 or 325 is a safe bet or a 525 or 528, you get comfy cars with a bit of go go 
1996 N Reg BMW 3 Series 2.3 323i
Calypso Red Metallic, Coupe, 2 Doors. ABS, Alloy Wheels. Silver Leather seats, Auto/sport mode, rear headrests, full BMW history, an exceptional car £5,495.
1997 BMW 528i SE AUTO, 1997,
P reg. montreal metallic blue, 2 owners, beige leather interior, f/B/s/h, cd player, aircon, f/sunroof, alloys, pas, r/headrests, c/locking, immaculate condition. £4,650 . . open 7 days.
1990 BMW M5 3800 cc
4 Doors, Manual 5 speed, Saloon, Petrol, silver Metallic. 17" light alloy wheels, 6-cylinder, ABS, airconditioning, alarm class III, alarm remote controlled, alloy wheels, boardcomputer, bumper and mirror in color, central doorlocks with remote control, chairs adjustable in height, electric mirrors, electric sunroof, electric windows, fog lights, frontseat(s) electric adjustable, full service history, half leather interior, immobiliser, metallic painted, mirrors electric, MOT at delivery, power steering, radio/cd-changer, sport chairs, spot lights. bmw fbmwsh by munich legends ltd £4,995 ono.