Your question has two parts: 1) what is a good reverse osmosis filter, and 2) what is a good filter for a refridgerator?
I can recommend the Whirlpool WHER25 reverse osmosis filter system from Lowes (see website URL below). I have installed two of them (including one in my own home) and have had no problems or issues with either one. Of course, you do need to change the filters from time to time, but that is the nature of the product. This system is slightly more complex than a standard filter to install (takes about an hour), but does produce excellent quality water.
We have a $35 in-line charcoal water filter for the refrigerator, which works well. Many high end refrigerators now have built-in filters, so be sure to check yours to see if it does. It is usually simple to remove (one twist) and replace.
Source: http://www.lowes.com/pd_129808-43353-...