Needed my 11 year old gas hot water heater either repaired or replaced, found these folks online (highest rated plumbers on Yelp), and had a great experience with them myself as well:
On Time - called them at 9am, their office offered an 11am appt and the plumbers showed up right on time.
Courteous, competent and professional - after listening carefully to my description of the problem (only getting a few minutes of hot water) and looking over the water heater, we chatted for a bit about repair vs replace and they wrote up a quote for each, no pressure either way.
I opted for the replacement option (having done a bit of research before their arrival), and ended up with a Bradford White that turns out to be highest rated water heaters on the market.
Bonus/Solid Advice - they did an excellent job installing the new water heater / removing the old, then offered to spend a few minutes touring the rest of my house's plumbing. This quick tour resulted in good advice that will allow me to fix up a couple minor annoyances on my own, and also a great reference for a reliable contractor (for an eventual bathroom remodel).
Long story short, after a couple horrible plumbing experiences (Beacon and another big-name chain), I'm relieved to have finally found a reliable company that's not just out to gouge me for all they can.
They don't currently accept credit cards. Not a huge deal, but just something to note.