That's not quite like asking "what kind of motorcycle is best for riding", but it's close. There are so many other questions you have to ask yourself in order to narrow the choices down:
Is this just for lagering or are you going to ferment in it as well?
How much space do you have?
I got a keezer that lets me have 7 kegs on tap but that took up most of the room in my garage. I use a mini fridge for my fermentation (lager or otherwise) just because I don't have the room for anything bigger.
How many fermentation vessels do you need to fit in said freezer?
If you get a chest freezer you may be able to fit quite a few. Mine is 14 cu ft and I can fit 5 carboys/Better Bottles in it.
How often do you brew?
Kind of goes with the previous question, but if you brew a lot of beer you are going to need more space.
How much money do you have to spend?
How is your back?
If you are older or have a bad back an upright may be the way to go so you don't have to lift a full carboy up and over into a chest freezer
I'm sure there are more but I'm on my 3rd ESB and I can't brain so well right now.
Basically I would recommend looking around the forum, youtube, and google for what people have come up with and judge that against what you think you want. If I ever get a three car garage I'll get a 21 cu ft upright freezer and convert it into a lagering fridge and keep the mini for ales. Right now I only have space for my mini fridge. Also, upright freezers that don't have the coils in the racks are hard to find and kind of expensive even on CL. I got my mini fridge for $20 and spent another $35 on a controller and all the cable/parts to wire it up. Grand total of $55 and I was in business. I can make an ale every week but when I make a lager I tie up the fridge for a while so I only make lagers when I have more than enough ale around.
I hope that helps a bit. The biggest thing to do is browse around and research what's available. I think that will tell you more of what you want to know than any of us could.