My choice in "retractable" leashes would definitely be the WALKABOUT by Aspen Pet:
Flexi Leash Classic Long 3 - All Belt Leash - 26ft Leads
The great lesson I learned with this kind of retractable is that it is a TAPE vs. Cord Leash.
I've seen too many owner's who walk their dogs on a Cord-style retractable leash that has frayed and all I can think of is just one good tug and snap...there goes their dog!
The TAPE-Style just gives me a better feeling of security than I ever had with a Cord-Style.
I think I got mine @ Petsmart for about the same price as the other style...maybe a little bit more but, well worth it in my opinion!