TransForce - When I was shopping, I liked the tire, the price, the ratings I could find on the web, plus positive comments (not just Jose!) here. I heard more good (and less bad) about TF's than a couple other major brands.
Michelin - Needs no introduction, anywhere in the world. That LTX series is a great tire. The XPS Rib, even greater, but not a traction tire. Our MH is just plain heavy. Not particularly butt-heavy, the wheelbase is enough to carry the weight without overloading the rear axle. But there are many where the rear axle is at, or even over, its load rating (GAWR). For those, I'd suggest the XPS Rib...
Duravis R250, that Goodyear, or something a little more robust.
Duravis R500HD - I've lost track of what Bridgestone did. R250 is a beefed-up tire. At least awhile ago, they had a Traction version, same enhanced carcass design as R250, just M/S, A/S, whatever they called Traction. I don't know if they still offer that, or their traction tire is now more equivalent to a Michelin LTX.
EVERY LT225R16E is "motorhome rated," but you get what you pay for. Materials, mode of construction, etc. determine the actual durability. Some of it is in the "Brand" but there's a little more to it than that.
Again, 21-ft Class C? Any Name Brand, your pick. Even Kuhmo (if I spelled that right).
Another thing I consider is: "Where can I get an exact replacement if one fails on a trip?" That leaves some of the off-brands out.