Set your budget including batteries and charger (100ish for these items). then find a rig that fits in the budget.
As others stated already. Axial, Traxxas, Vanquish Products, element are the most well known/popular/quality rigs.
RedCats Gen 8 is also a decent rig, at least on par with Element IMHO.
Any of the name brand rigs mentioned have upgrades from various manufacturers for them.
Some low cost things and some high dollar items depending on what/where/how etc.
Find an RTR that you like, 2 speeds are ok, but generally are more of a gimmick with crawlers, but not totally useless, just not one of the go to things we often wish we had if we didn't have it.
Otherwise I think the Axial are most popular, followed by Traxxas and Vanquish then RedCat then Element in terms of units in use/sales,.
In terms of quality, I would say Vanquish, Traxxass, Axial, Element, RedCat. (only look at the Gen 8 or 9 from RedCat).
If you are into Scale side over Performance they all do pretty well. But if you're leaning strictly performance, jump to the Vanquish rigs.