Ah, I was hoping you'd slip up and give a price range
...
I do have three other suggestions.
Infiniti G35 2/4 door. There are more then a few 2006/5's in that budget range. You gain a lot of performance, esp. being a proper RWD car, and still in the Nissan 'family.' The ******** isn't the highest quality I've seen. The fake metal feels especially cheap.
Cadillac CTS. Plently of 2006's in that price range. Opinionated car, esp. at the moment, but should be the easiest to find with low price/mileage/etc. ******** isn't a world-beater, polarizing as well, but decent and higher quality materials. Lots of car for the money. Proper RWD as well. Look for one with the 3.6L V6.
Volkswagen Passat, preferably with the 3.6L V6 over the rougher 2.0T. It's not quite as peppy as a 3.5 Altima, but gain a lot in other areas. It's ******** is down right gorgeous, very high class, second only to premium German brands, safety is well known, and a bit more room in all areas. Available 4Motion all-wheel-drive as well. A 3.6 model makes a good drivers car too. Tons of options as well.