If your not very experienced Humminbird is really user friendly and easy to learn with
If your great with sonar (I'm assuming your not or you wouldn't have asked this question) Lawrance is a good option
I run humminbirds on my boat and love em... I consider myself pretty good with electronics and my Humminbird units do everything I want my electronics to do for me
There are some great deals out there right now on the discontinued Humminbird models now that helix and onix are out