I've heard alot of reliability problems with the Line 6 DL-4s, but they do sound good. The Boss DD-20 is cheaper and just as good, the DD-6 is also good, but the DD-20 is only $20 if you shop around. I've also read some good things about the Digitech X-Series Delay. Another nice pedal is the Visual Sound H20 pedal, chorus and delay in one pedal, both are more basic than the Bosses, Digitechs, and Line 6s but are supposed to sound great, and isn't that the most important part?
Roger