I also have a very expensive dynamo system on one of my bikes which I like very much but if you're looking for something inexpensive, my money is on the LED lights that run on standard batteries.
I use a cateye 3-LED light for night riding. I think it's great as a be-seen light, but it's no good as a see-the-road light. If you want an inexpensive see-the-road light you want something along the lines of 3-watt halogen or 1-watt LED at a minimum. For inexpensive lights, AA or C or AAA batteries are definitely the way to go. At my house we have a bunch of NiMH AA's, which work with all our bike lights.