What shoes to wear with straight fit jeans?

Depends on the look you're wearing them with. But a good pair of Converse Jack Purcells (not All Stars, Jacks are much more stylish and comfortable) will carry you through the seasons, through many different looks, and will last for at least a year. They're great. If those don't fit your fancy, maybe go for a pair of Clark's Desert Boots; they're as clic as Jacks, and have a rugged, yet stylish, look about them.