One place to compare ice-making machines is 10rate. It has a list of the top 10 under-counter ice makers of 2015. Comparison criteria include quickness and ease of ice making, ease of installation and the amount of noise produced.
Other points of comparison include whether an ice maker is freestanding or under the counter, storage space, removable bins, insulation, lack of condensation, frost buildup and maintaining low-enough temperatures.
Ice makers that generate about 12 pounds of ice daily can be purchased for about $200. Larger models can cost up to $1,000 or more. The budget recommendation from 10rate is the EdgeStar IB120SS, which costs $295 and produces 12 pounds of ice a day.