More engaging/interactive ways to learn grammar/sentence structure?

Note: These aren’t services but methods for addressing common grammar resources’ dryness.

If you don’t mind using manga as a vehicle for learning grammar, I like to recommend Japanese the Manga Way for this purpose:

Another route (which has less direction and requires a bit of perseverance) is to start reading native material and look up what you don’t know as you go. This is easier if you join the Absolute Beginner Book Club, as you can ask questions and get answers targeted at the material being read.