The A20T is our favourite in the A10 and A20 ranges from Geeetech.
Providing a 250mm x 250mm x 250mm build volume which is more than sufficient for most people, and multi-colour printing.
This allows you to easily print almost any colour you like using their software. Whilst their software isn't ideal, and their default slicing profiles can lead to some stringing, we've had some pretty good prints from this range of machine.
The mechanical build, for the price, is excellent, however we advise using Cura Slicer instead of Geeetech's Repetier host based solution, as it's much more intuitive and produces nicer prints.
Overall, for the price, you get a lot of printer, at the expense of a few parts such as extruder feeding mechanism being slightly lesser quality.
It's hard to beat Geeetech on price that's for certain!