We - well, Jonathan - has had this guy since 2007. And it has probably been the most-used appliance in our kitchen (because back in the day [when I was still taking in the coff]), we were both having about 2 cups a day).
For the most part, this coffee maker has been great. I seriously cannot recommend enough the single-cup brewing system. You always have a delicious, fresh cup with no end-of-the-pot sledge. It's also handy for instant hot water whenever you need it.
We didn't really have any problems with ours until about a year ago when it started telling us more often that we needed to "de-scale" the system (ie, run vinegar through it to remove the hard water buildup). Also note that we'd never de-scaled in the first 3 years we had it, even though they recommend doing it once a month. So part of our Keurig's untimely death could be our own fault. But recently, we would de-scale and then it would tell us 2 days later we needed to do it again. It started to mess up every time it made a cup (ie, only a little bit of liquid would come out and then you'd have to run it again and double the amount would come out). Then, this past Saturday, water started pouring out the back of the machine while brewing. That was when we decided Old Trusty had brewed his last cup.
RIP Keurig - you've been good to us - you've pepped us up in the mornings and helped us attend late night concerts. We'll miss you.