It does not hurt to shop for you own title insurance but there are a number of things you should consider. In Colorado it is usually the seller who pays for title insurance so they are usually the decision maker of which company to use. The buyer is the beneficiary, so they may want a say in it. Title insurance is insurance for future claims and many title insurers have gone out of business in the last few years, so the buyer may not want to take a chance on a smaller company. Not all policies are equal, find out what is covered and what are the exceptions. Not all closings are equal, it is scary to have a closers who seems to be winging it. I have seen where the closers had not filed the proper paperwork and it was not discovered until the house is put back on the market. You may not want to rely on your Realtors recommendation, but at least carefully consider it, they use title companies all the time and have valuablle experience.
Reference Limk: http://titlecompanies.net/