Suzuki Club UK

I like the spray on/wash off stuff... It's like oven cleaner but for cars

Be careful if you're asthmatic though!

Degreaser, a few different size wire brushes, lots of rag and lots of elbow grease
It's a lot easier with the engine out and even then it takes a while to get it nice and clean.

For the easy to get to bits you can even use a wire brush attachment on a drill.