I'd recommend anything that's 20/20 waterproof breathability. But in the past I owned a pair of Sessions bib pants that rocked for a few years. I heard good stuff about Volcom's bib and I am seriously considering getting Libtech's bib this year if funds allow.
i wear a pair of XL Arc'teryx Theta SV bibs.. they're sort of 1/2 length bibs.
they have some curve to the legs but the XL is baggy enough on me you can't really see it too bad.. i wear a M/L in a normal snowboard pant; 34/30 jeans.
i've got 3 seasons on these and they're still going strong. i put 6 "80-100 day" seasons on my last pair of arcteryx pants before these...