Nissan Sentra, Honda CR-V, or Honda Civic?

Hi all, I need some advice. I'm looking at a 2006 Nissan Sentra 1.8S Special Edition automatic for sale with 83,000 miles on it that I really like but all of a sudden I'm having second thoughts because I'm currently driving a 2001 Honda CRV 4WD LX automatic with 146,000 miles on it and it also runs great. I just want to know, which one is better? Should I go with the Sentra or should I keep my CRV even though it's a lot older and has a lot more miles on it? Or should I look for a Civic? I'll be going to school soon and will need a good commuter car with great gas mileage as I'll be driving 35 minutes west of my house to school as well as to my two other jobs which are 30 minutes east of my house, so I'll be doing a lot of driving. The CR-V is okay on gas, I average about 20-21, and really like the extra cargo space (which is why I bought it), but I never haul anything and most of the time, I'm the only one in the car, so it's a bunch of wasted space. I love the Sentra because it runs well, has low miles, gets great mpg, and has the factory subwoofer and premium sound stereo. I'd just like some opinions, which car should I go with? It'd be long term too, so reliability is a plus. Thanks!