I'll of course always recommend the Taranis but it is not very user friendly. However, it offers TONS more features than almost 99% of most transmitters out there. Replacement parts are cheap and easy to install, build quality is pretty good, and the radio link is solid and should never be worried about IMO. I've had nothing but good experience with my Taranis.
The RadioLink AT10 is ok, but doesn't offer S.Bus which is good if you plan to fly later and the AT9 is also 10ch, has more features, and is cheaper. I have both as well and the AT9 I like much better. Both of these transmitters also come with an extra self centering stick as well which means you have a tank ready transmitter right out of the box. The programming is super simple, probably the most user friendly I've seen.
The i-10 is also a great radio as well though the receivers are kinda big. FlySky has a pretty decent radio frequency and offers IBus as well so you have that option instead of SBus for flight on some controllers. They do not come with an extra self centering stick and you will have to contact a vendor (I suggest
www.ForceRC.com formally known as Diamond Hobbies) and ask them if they have a spare one to purchase before you get the transmitter. Otherwise the i-10 is great all around and is great for the price and has some of the best looks of any transmitter besides JETI transmitters IMO.
Spektrum is very expensive but has great customer service and parts. You do not get any special features with a Spektrum over another, but you will be able to keep it for a while and they do have trade-in options for later when you want to upgrade.
If it is just a tank model I would first see if you can get a spare gimbal for the i-10, if not then the AT9 or AT10 makes a good second choice. If simple is what you want then these two are great.