Battambang is Cambodia's second largest city, but it isn't on the main tourist trail, and I have to say, not without good reason. Battambang is certainly a nice enough place. I would even say that the people in and around town are some of the nicest you'll find in Cambodia, if not Southeast Asia. The center of town still has some rather pretty old colonial buildings, and there are also some Angkor era ruins in the countryside around town.
The thing is, the ancient ruins aren't much compared to Angkor, Kampot has, in my opinion, a better array of colonial architecture on offer, not to mention the ocean nearby, and Battambang is rather hard to get to. There are no flights, so the only realistic option is road travel, which takes four hours from Phnom Penh or three hours from Siem Reap.
It's not that I don't like Battambang. I loved it, in fact. But, it's a place that is only going to appeal to certain people, mostly those that have "been there, done that" and want to get off the beaten path. Battambang is a place for people who have learned to slow down and enjoy the smaller things that a provincial town like this has to offer.
Most of the sights, such as they are, are in the countryside around town. There are impressive ruins - though nothing like Angkor - at Ek Phnom and Prasat Banan. The area around Battambang was one of the last strongholds of the Khmer Rouge, and chilling memorials to the terror they wrought can be found at Phnom Sampeau and Wat Somrong Knong.