I have a spare fridge sitting in the garage. Its my beer fridge. I strongly considered converting it to a kegerator, but there were 2 main issues I found with it (for my situation).
1. I didn't want to permanently damage the fridge. Unless I wanted to only use party taps, I'd have to drill through the door to add the Perlick taps. I didn't want to do that.
2. Size. Depending on how I built a shelf inside the fridge, I'm pretty sure I'd only be able to fit 3 kegs plus my CO2 tank. I have just started kegging, but I already know that I'll need more space than that.
Taking these things into consideration, I decided a keezer was best for me. I bought a Frigidaire 12.9 cu. ft. model for $329 (with a $50 rebate), and I can potentially fit 11 kegs in it with a collar. I don't ever plan on having 11 kegs, BUT I could. What I plan is to have 4-6 kegs at a time, plus several carboys for lagering or cold crashing, and some bottles.
By adding a collar, I can put the taps, gas line, and temp probe through the collar, so I don't actually have to permanently alter the freezer. If I ever quit brewing, I could take the collar off and simply have a normal chest freezer again.
That may not be important to some people, but it was to me. And it may end up being important to my wife, who hasn't seen the freezer in person yet, and also needed to be sold on its multiple functionality possibilities.
Kegged: Galaxy/Vienna SMaSH Pale Ale
Kegged: Prohibition Lager
Kegged: Ricks Red Ale
Bottled: LH Milk Stout Clone
Primary 1: Biermunchers Centennial Blonde
On Deck: Milk Stout, SNPA clone, maybe a pale ale so I can use my homegrown hops to dry hop.