Most Helpful Guy
You can try JeansWest.
Most Helpful Girl
you're fortunate... if you'd asked that question 5 years ago, you probably wouldn't get any good replies, as there were barely any online stores that had any stylish options (i know, as i spent hours googling back then, lol--I'm 5'10" with a 34 inseam, btw)
these days though you have a ton of options as more and more retailers offer tall inseams.
I've always had good luck with Nordstroms and H&M. (particularly JAG and NYDJ labels... though Macy's carries those too I think) Old Navy has a limited selection, Duluth has an okay selection (i just ordered from both of those--though be careful of Duluth's size charts, the waist measurement is off)
There's several specialty stores too (longelegantlegs. com and us. longtallsally. com, for example). But be careful, they have more options, but can also be insanely pricey
I personally go to makeyourownjeans. com more often than not... that way I don't have to worry about other measurements not fitting right--but definitely visit a tailor before going this route... it'll save you a huge headache.