Suzuki Bandit 600
BMW R1150R (Roadster)
BMW F650 / Aprilia Pegaso
Honda Nighthawk 750
Those are all in the new category, all of the Japanese bikes under $7,500, the rest under $10K (US$).
Possible consideration could be given to some of the "hooligan"/performance naked bikes, such as the Ducati Monsters, Triumph Speed Triple, Yamaha FZ-1, Suzuki Bandit 1200, Kawasaki ZX11, etc.
Other possible cruiserish beasts would include the BMW R1200C, the Victory, and the hordes of "metric" cruisers.
What type of riding does he want to do, and how much is he willing to spend.....