I'm really liking my current setup for staying dry:
I have the Kokatat Hydrus Tempest dry pants with the integrated goretex socks. (pricey, but I wear them more than my waders these days) Worn with sandals or wading boots, they'll keep you dry in rain, or standing in water for a short period - long enough to launch, etc- but will leak if you try to wear them for extended wading. The wide neoprene waistband is comfy and snug enough that if you went overboard, air would likely get squeezed out but water would not gush in.
However... even with thick socks underneath, having wet boots over them hanging out in the breeze on a cold day left my feet frozen. I now wear knee high Muck Boots (Forager model, sized up one size) over them.
High enough to launch & trailer without getting wet, very comfortable and flexible, feet stay warm (fished all day Wed in sub 40°) AND the smooth, no shoestring or straps surface keeps line from catching on my feet. Bonus, they shed water instantly, so I don't flood my car mat getting in & out while trailoring! They fit snugly, but because they're so flexible, they slide on/off easily, so if I needed to jettison them, they could be kicked off.
If you fashion guys think they look dorky, I'd suggest you accessorize them with one of these
kokatat.com