it would be nice if you could try before you buy, but then again, that'd be rather nasty.
We get to try them on here, but you MUST keep your original underwear on when you are trying them. Then of course you have the problem of trying to work out how they'd fit if only you weren't wearing 2 pairs! Not sure quite how much I trust people to do it even if they have been reminded 3 separate times before they get to try them on, and you never know if someone has returned them pretending it's an unopened packet (we have much more favourable return laws here, it often seems) so I always put them in the wash before I put them on! I also wish you could try clothes on after you've put them through the laundry, but that's a whole other issue!!
I agree to try different cuts and styles, and particularly ones that are side-seam free because then when they are a bit tight they don't dig in you.
I am also a big pants person. I don't like large pants as in high rise briefs or "granny panties" or anything, but I do prefer my underwear at least one size larger than my regular size, usually 2 sizes. It doesn't seem to matter what size I get, though, it never fits. I custom made some underwear once cos I got fed up. About 10 years ago one company did a major redesign of men's underwear when they found out that the navel to pubis length did not increase in larger waist sizes when it had always been assumed it did. I am sure the same research is still missing in ladies' underwear because when I buy a larger size of something like shorts the *ahem* gusset length is designed for me to be 8 feet tall! I need a UK8 in gusset length with a UK16 hip width, so I went out and bought a packet in each size and sewed them together, but I wouldn't routinely do that, I just got real fed up one day!
I buy the Hanes boyshorts. They're pretty snug if I buy a size medium, and stay on well without "rolling down" (anyone have that happen before with a really tight pair of undies?! so annoying!) they're my go-to undies basically all the time. I love them so! Joe boxer has a good selection of them, too.
I prefer the cotton hipsters (made by Hanes or maybe FOTL?). The last time I bought them though they were too high and too big. They either changed their sizing and cut or they were a mistake. I just wear those for TOM now. But my biggest problem with my underoos is I have an awful case of VPLs. No underwear that I have found can cure it. I know that it is because my backside is loose and yes, I am doing squats and lunges. I don't think that it is going to get much better at this point. Does anyone have any suggestions for me? I am not comfortable with a thong and boy shorts seem weird to me. I'm afraid that they will bunch up in the front.
For VPL, my mom swears by microfiber underwear. But I find them a bit too sweaty. I think that's an individual thing though because I can't imagine wearing nylon or anything but cotton down there, and other people don't seem to have that issue. They have a bunch of different microfiber brands in Kohl's, I think there's even one called "No VPL" by one of the big manufacturers like Hanes or Bali.
I had to buy some that were my size-ish but not cotton (which I always used to wear) = they have some spandex - I couldn't stand having my underwear baggy, loose and FALLING off! But- as long as I am losing weight I will definitely suffer this!
I'm so picky when it comes to underwear. I only like the hi cut ones from VS. They have to cover my pooch and my buttcheeks. I'm having the same problem too though. They are starting to get too baggy in my butt and now I have to pull them all the way up to my belly button. I feel like I'm wearing "granny panties". I'm afraid to go down to the next size because I hate when my underwear are tight on my legs
That's the kind I love too! I recommend the VS hi-cut briefs very much, but they DO have saggy butt syndrome. I personally believe that's because they get stretched out with time / washing / wearing / butt expanding and contracting. You know...the usual. I find that the VS underwear that is NOT cotton does less stretching. Perhaps try some of those?
Good luck! No one deserves evil panties!
Underwear is just one thing I will not compromise on and always bought new as soon as I went down sizes. They need to be comfy!
The absolutely most comfortable underwear EVER, at least in my experience, is it.se.bit.se by French Dressing. They're like enveloping your behind in wonderfulness. I'm not kidding at all! I will wear no other brand now.
Oh, right, I found them at Costco but they can also be purchased online. http://frenchdressing.com/home
I actually used to wear underwear that didn't fit me, those 5-packs from wal-mart, then I gave in and bought some by-the-pair underwear, and WHOAH. When it fits right, underwear is SO COMFORTABLE!
My advice is to buy cotton underwear, all cotton or mostly cotton, buy the smallest size that doesn't feel tight, and if that size feels big, then go home and wash it in warm water and then dry on hot.
They need to be comfy! 
