Russian,
I highly recommend this one: **broken link removed**
It is super simple to use and quite accurate. It reads 1-2 points higher than labwork results which I have compared many times so I know it's consistent.
With most centrifuges, you have to buy molding clay to seal one of the ends of the tube and then you have to get a card to read the crit, look at the color, both of which usually come separately. It's kind of a pain in the ass.
With the one I linked above, it's simple. The gauge is on the actual centrifuge so no card you have to buy separately so you can see your crit reading immediately after the blood is spun.
Also, the one I linked above comes with a lot of tubes that don't need to be sealed with clay. you just draw blood, put in the tubes, and then spin them until the blood is packed (I always did 3 minutes).
The guy you order from is a Harvard Med School guy and he offers a lifetime warranty.
I am very happy with it.