Good off topic question!
SLO is in the running, but I also like Pullman. Both are much more similar than different, and true college towns. I've spent a fair amount of time in each, at different times of the year. SLO has the ocean close by; Pullman has mountains & skiing. Pullman has winter and spring slush; SLO has a biting wind that time of the year that is only rivaled by the lower Columbia River areas. Moscow and Sonoma could make a case, though both are a bit more than just a college town. If you are willing to count somewhat larger (50K to 70K-ish) towns as "college towns", then you could make a solid case for Corvallis, Davis and a few others...probably not Logan, though, because although it is somewhat college towny...well...this won't sound PC...but how do you have a legit college town in all senses of the word in Utah? Stanford has argued that the farm is essentially a college town; I don't buy that, but there is a case to be made. Eugene and Boulder are simply too large to have the college town vibe. In some ways Humboldt state ("Cal State Weed") is a college town. You will note that I'm focused on the west. There are a lot of college towns east of the Mississippi, particularly of the liberal arts variety. I've always wanted to visit Faber College....