If I had unlimited space, I would have rather had a keezer. However, the space at my house (at least the space that is available for my boozery) is limited. So, I chose the upright refrigerator. This took up less horizontal space, and I could fit a wire shelving unit on top of my kegerator for additional space. If I had a keezer, it would take up more room, and I couldn't stack stuff on top unless I was willing to move it all if I needed to open the keezer lid. One additional advantage of the fridge is that I have the freezer available for frosted mugs for my blonde ales and pilsners, storage for my hops, and ice for mixed drinks.
Also, dont buy a used fridge or freezer from craig's list. If you're going to put the money into a nice keezer, you dont want the freezer dying after 6 months. Spend a little more and buy a brand new one.
I strongly disagree with this, unless money isn't an issue. If you have money to get whatever you want, absolutely go new.
However, if need to save money, but still want a kegerator/keezer setupd, CL is the way to go. I'm a poor medical student, with two kids, too much student loan debt, and too many hobbies. Used was the way to go. I got my fridge on CL for free. I then sunk precisely $0 into drilling the holes for my taps. If it dies tomorrow I have the option to buy new or peruse CL for another good deal. I can then drill a few more holes and transfer over everything except my stickers and the only cost I have is disposal of the broken fridge... And this is assuming I can't fix it, and I'm pretty good with fixing mechanical stuff.
Same goes for a keezer build. Building a collar isn't exactly rocket science, and doesn't have to cost a lot of money.