I've been reading a few threads on here recently about avoiding the dreaded thigh chafing for the ample of thigh in summer.
Even after losing weight it still plagues me 
I found a solution in the form of Florence & Fred "magic seam free shape wear short" and they're only £5!
They are a bit shorter than the sloggi option, stretchy and pull you in a bit too (have a nice thick waistband. They don't find as constricting as the usual spanx type and reckon I could wear then in the heat abroad too!
One thing, they do look very small indeed when you first look at them, but they do stretch A LOT. I got the size L, and I'm about a size 14 usually (my thighs are more towards a 16 though) I think I could have squeezed into a medium though if I'd wanted them tighter.