I've had Lowrance, Eagle, Humminbird, Garmin, Raytheon, and Interphase units over the past 20 years - just can't find the right boat

. The Garmin and the Raytheon were the most reliable and never went back for repair. I like LED screens with at least 480x480 pixels to really separate fish and bottom type. Color helps with that, but isn't necessary. I always get high power units because it's needed in saltwater - not so much in fresh. Match the power output to the depth you'll fish and don't buy the cheapest unit you can find. I'd say shoot for something around $150-$200.