For our condo sale, we used Ed Jelinek, who was awesome and amazing. But for the buy side (seller pays realtor costs for both sides), which is much simpler, we used REDFIN. You've probably used Redfin to search real estate if you're at all into that sort of thing. Redfin is similar to realtor.com, but it also tells you when and for how much the property sold for previously. My favorite redfin feature allows you to view houses SOLD in the past 3 years (and some even farther back), at what price, the pictures, etc. To do so, type in your search criteria, and then click "more options." The far left column has check boxes, check the blue house for "Sale Records." This is a great way to understand what the market is doing in the neighborhoods you are perusing. In the past 3 years, there has only been 1 house sold on our entire block - OURS.
And of course, the BEST thing about redfin.com, is that redfin pays the client half of the commission. For example, currently in the Chicago area, the buyer's and seller's agents each receive 2.5% commission. Redfin will pay 1.25% of the sale price to YOU. This rebate practice is actually illegal in some states - those realtor lobbies are powerful - but we think it's a great way to keep realtors competing.
We thought our Redfin realtor would be totally clueless. After all, as a Redfin user, it is your job to select the houses to view, and they set up the appointments and send an agent along with you. We had a great agent, who knew what to look for, was very responsive on email, and we were lucky to get the same guy, David Yochum, everytime. Redfin worked out really well for us.
Note: if you're going to use Redfin, you might want to avoid talking about it with your realtor friends. Apologies to my realtor friends.