Although my shop is set up and wired/plumbed for two lifts, so far I only have a Rotary asymetrical 2-post. It is a commercial level lift and it is a great product. At 10-years old, I have had no problems with it. The higher end Bend-Pak lifts are also pretty good. I would avoid the imports and the cheap "parking" lifts. Keep in mind you get what you pay for. Do you really want to be standing under the cheapest lift?
Things to consider are weight capacity, height, interlocks and quality of construction. Although I have a 2-post and plans for a second 4-post lift, if I could only get one lift, I think I would get a 4-post. They support the vehicle much better and are less subject to a vehicle moving/falling if the weight shifts, such as removing transmissions, engines, rear ends, gas tanks, etc. They are easier to work on suspensions, but if you get the rolling jacks for a 4-post, you can have the best of both worlds. Personally, I would not have a movable 4-post. I do not like the idea that the lift legs are not firmly affixed to the ground when I have 5000 lbs or so over my head. Also, at 6' 3" tall, I look for a lift that will put and hold both a hot rod (lowered suspension) and truck (higher suspension) high enough that I can stand up under them. It really gets to your back when you have to hunker down to work on things overhead without being able to stand up straight. Lastly, make certain that your floor is strong enough to handle the load of mounting a lift to it. A lot of residential homes do not have the thickness or quality of concrete necessary to support mounting a lift to it safely.