If you are an experienced rider,you might want to take a look at the new suzuki Bandit 1250 or B-king. Those a re really big bikes. The B-King is said to be not well suited to two-up riding, however.
How about getting your wife her own bike? No matter what bike you buy, there can´t be much room for comfort left behind a guy like you
If you ride solo, a big dualsport like a BMW HP2/Megamoto or KTM 990 Adventure/950 Super Enduro might mork for you very well. They´re especially good for the knees, the angle is still comfortable even for very long-legged riders.