Where is the best place to take a road trip in the USA??

Do you know where they rent the big trailers to take a long road trip?

I live in Texas, so where would be a not too far way, nice place to go to?

That would be California and Arizona. That way you could go to Yosemite and the Grand Canyon all in one trip.

Travel along route 66!
http://www.historic66.com/description/

NM or AZ would be within a reasonable distance, and certainly loaded with anything you might want to see.

Without knowing where at all you are in TX, I find West TX to be desolate, boring, and prone to ugly weather, and the best way out is I -10

WWW general search using keywords. for "trailers/Rv's/ etc.

Since you asked BEST, initially The Pacific Cosst Highway, and Rt. # 80 in late Spring/ Summer through the Sierra Nevada's is as close as it gets to best, in my opinion. 66 is OK, but not as glamorous.

You should go to Memphis for BBQ and blues and Elvis. If you really had time, I would travel the Mississippi all the way up here to Minnesota and see all the great river towns. Then you could hit I-35 and head home to Texas.