The honest truth is that everyone is just going to recommend their manufacturer of their choice with these threads. I could give you a list of reasons to get a Serpent SRX2 MM, such as its exceptional durability, how easy to drive it is, and how you get a completely capable car straight from the box without the need for hop-ups, yet it's still one of the cheapest 2WD kits out there.
However, 1/10 Off Road is such a competitive class that the market is pretty much at stalemate. It's much like 1/10 TC - all the cars look the same for a reason. There really is no car that is light years ahead of another - as long as you can find spares easily and it fits your budget, you'll be completely fine. Astroturf/carpet racing and a big push in quality has forced manufacturers to take the class seriously. Today, all cars are made to such a high standard that any cars which are fundamentally poor (take the original 22) show themselves up, and manufacturers have to take note to prevent poor sales. Even first attempts are exceptional - see the Carisma 4XS - a car that, besides rear hubs which are a tad too weak, is virtually impossible to fault quality-wise. Even the less well-known brands, like VBC and PR, are producing reasonably priced kits with great support from distributors and shops alike, all to the highest standard. If you took one back 10 years, and lined them up next to your average B4 and XXX-BK2, they'd look light years ahead.
Long story short, any modern 1/10 Off Road release is a strong enough package for you to buy it and enjoy running it. All have their weaknesses, all have their strengths, but you can't really "go wrong" with any purchase. The only car I know of which simply isn't up to the job for a 2015 kit is the TRF211XM, which is a very nice quality kit, but is simply overpriced, has too little UK support, and lacks some of the very basics that are to be expected on a car in 2015 (such as 12mm hexes). Other than that, see what people at your local club run, and pick whatever kit you like the look of.
