For a color printer, we bought a couple of Ricoh Aficio SP C811dn. They're *very* reliable when running standard-weight paper, and when running standard-size heavy-weight paper. For non-standard-size paper, look elsewhere. We have some of these in printer configuration, and some of them in copier configuration - I can't remember which model # is the copier equivalent of this printer, but it works just as well.
We also have several Canon imageRUNNER C5185i copiers. We've had a few issues with the output stacker/sorters, but no unexpected problems with the copiers themselves, as far as hardware goes. Note that there was a firmware release out there that caused them to take for-freaking-ever to print a PDF document... apparently that was resolved, as I haven't seen that problem in quite a while now.
There's some Xerox WorkCentre crap around here too. One of them is a 5645, I don't know which others models we have... but they're all complete garbage. 100%. Don't get Xerox *anything*. Frequent paper jams, board failures, shitty drivers, if it can possibly go wrong, it does.
Finally, Sharp. We don't have any color Sharp printers/copiers, but we do have a few monochromes. I hate them. They're a pain in the ass to manage. The web management console is straight out of 1998 -- they haven't quite gotten the hang of how to design a functional management interface. Then again, that shouldn't surprise me - the user console on the front of the copier is still the same as it was on most copiers back in the early 90s. They're *extremely* user unfriendly. Our users complain about frequent paper feeding issues, also.
Hardware manufacturer aside, you need to find a good company to use for service. I've had excellent experiences with Ikon and Gordon Flesch -- they always seem to take care of us. While no company is perfect, they've also corrected any mistakes that they've made. With ComDoc and Modern Office Methods, on the other hand, I've yet to have one good experience. Perhaps it's just the employees in my immediate area, but their employees (both sales and field techs) seem... subpar.