My $0.02 on this as well, as I fly both fixed wing and multirotor:
The preferred transmitter for multirotor is FrSky radios. From what I understand, they are a more robust radio for less cost. That said, they're a pain to get set up initially, as they have a steep learning curve to get things set up. I also don't see many people flying fixed wing using FrSky transmitters, at least, not here in the San Diego area; most are either Spektrum or Futaba.
I bought a Dx6 Gen 2, brand new, for $200 when I got my Blade Conspiracy in April of this year. Turns out this was a great purchase, for several reasons:
1) My father bought an Apprentice 15e; I was able to fly it by simply making a copy of his plane's settings, straight from his transmitter, and copying it onto my SD card, which I then put into my transmitter and uploaded. No need for a bind connector on the receiver, no setting of trim, or throw, or anything like that - it was all configured to fly the same way he did.
2) The radio can store settings for up to 250 different planes. This is a LOT, but it's possible you'll fill that up. How so? Well, if you share planes, like I mentioned above, you'll get all of your buddy's planes in your transmitter when you do the chip copy. If he's got 5 different planes from your 5 planes, boom, you've got 10 planes you can fly now. In addition, if you have a wireless USB dongle that you use to connect your transmitter to your computer (I have one, and so does my dad) that takes up another plane setting. Sure, you can just re-bind planes/drones every time you go to fly, but if the receiver's sealed inside your plane (like I have on my Sea Duck, as I want to keep it waterproof), re-binding every single time you go to fly is a pain in the butt.
3) Lots of people at my field fly with Spektrum. Now, yes, this is a bit of peer pressure to go with what everyone else has, but the plus with this is that if you need help getting it set up, the guys at the field who have your radio (or a similar radio) can show you how to get in to settings to do things like differential thrust with a twin engine setup. Support from friends is another big reason why I went with the Spektrum over the FrSky radios.
All this said, there are some wonderful radios out there that are not Spektrum. Futaba, HiTec, Graupner, FlySky - they all are comparable. But, if you want to buy a BNF kit from most local hobby stores, odds are it's going to have a Spektrum receiver and be ready to configure to that type of transmitter as soon as you take it out of the box. It's a "sufficient for most" radio. If you can pick up a used Dx6 (and I would recommend the Dx6 over the Dx6i because of the larger amount of planes you can store), it's worth the purchase, in my book. Yes, it's more expensive than the DXe that Geeto referenced, but that is a VERY basic radio, and if you wish to tune it, you have to have either a special Bluetooth module to sync up to your phone or a cable to connect to your PC to configure it. It's usable, yes - but honestly, it's a LOT easier to go scrolling through your radio to change settings than to have to hunt down a cable to connect every time you want to change planes.
