I have a Lowrance LMS160 and I am real happy with it although its mapping is a little primative and doesn't have much memory it still suits my needs very well.
If i was in the market for a new one I would go color with the new LMS-332C its got a ton more memory than mine better resolution and its much more powerfull I think it has 4000watts of power. I don't think you can go wrong with Lowrance, I had to call there customer service because I was having trouble re-using my boats existing transducer and they were outstanding to work with. A++++ on support.