I've used Martin Plumbing and Heating three times now, and with excellent results. They are not "cheap" but their prices seem fair for the quality of work they do. Here were three different jobs:
Job 1: Linkage under sink dripped. I tried to fix it, but once I got one sealed right another one leaked. Martin came over and came up from the truck with any necessary parts. They rebuilt it, and it was rock solid for years. They were professional and courteous and knew exactly what they were doing.
Job 2: Drain backup between two bathrooms. Not only would the water not drain, but it would fill the opposite sink in the other bathroom as well. They snaked it (and had to go really deep) and pulled out a whole cat's worth of hair. Again, fast, efficient, effective.
Job 3: Biggest job ever was to replace all the radiator valves. The old ones leaked and we were about to redo the floors. Not only did they offer two types of valves, but they took the time to explain each and why the existing valves didn't last. They took the time to make sure the radiators were properly drained in the entire apartment line. They tested everything before they left.
You might find cheaper, but I don't think you'll find better. I'm practically looking forward to Job #4.