There are tons of things to consider when selecting a radio, worth a read here:
Which surface radio system is the best?

As for me, I am extremely pleased with my 3 year old Graupner X-8E, this is the only brand that I know which offers a 2 year warranty, plus replacement Rx's are around $30.

Key features that are most important to me are:
1) Steering speed, absolute must have, many budget systems lack this feature
2) Drop down steering, I prefer to have the steering wheel aligned with the throttle trigger
3) Adjustable ergos
4) Easy to navigate menu

I have bounced around between over a dozen budget brands of radios as well as the following name brands and here is my personal order of preference for a mid-range system of the brands that I have personally owned:

1) Graupner
2) Sanwa
3) KO Propo
4) Radiopost

I have also tested Futaba (not actually owned one) and feel they are a wash with Sanwa, Graupner rises to the top of my list because they offer more features for the price for a mid-range system over anyone else. I also find that Graupner is the easiest to navigate with their color touch screen, not many mid-grade systems offer this feature.