[HUE]

Grammar books by their very nature are usually boring. But I agree with Clive in that Raymond Murphy is pretty good. The resident grammarian at my company likes the following:

1. Oxford Practice Grammar by George Yule
2. Exploring Grammar in Context by Carter, Hughes, and McCarthy

Unfortunately, I'm not at the office, so I can't ask what makes these especially appealing.

Books aside, perhaps the best piece of advice is making sure you put into practice what you learn. If you look up a grammar point (or vocab, too), make sure you use it as many times as possible at first. You'll get used to new language much more quickly, and you'll be less likely to forget it.

Good luck!