The Kossel Mini, through experience
I bought one of the Chinese clone kits of these machines, and once I finished wading through the Chinglish instructions and videos, I found some really great resources online to help me with setup.
The delta printer is not for the faint of heart as far as setup is concerned, but once you have it going correctly, it is one of the most reliable rewarding and fast bottom of the range printers I have seen so far. I have built and set up various i3 clones, and a Makerbot and none of them in my mind compare to the Kossel. It prints the same part in 75% or less of the time on average, with the same quality and resolution.
The only major downside is the build platform size, which ends up being a maximum useable of about 140mm round, although the height of 250 is quite awesome.
Overall though, I have printed the majority of my smaller parts, and some large ones in sections on this printer, and I find it's speed and ease of use (No moving table for minor height adjustment being one) far outweighs the pain of initial set up and tuning.
Overall, I would recommend this printer to anyone who has limited space, doesn't mind tinkering a bit to get it going, but wants something that is ideal for small items and fast prototyping.