My husband does not own anything that can be considered slacks, trousers or dress pants, and at this stage, I HIGHLY doubt I could get a pair on him. I'm not going to waste money on a pair of pants he'd wear once and never again - especially since I'd have to order them in size 32x38. I have enough trouble ordering jeans!
That said, I "dress" him for nice events in his "good" jeans and a nice button up shirt (he's got a nice white one with thin plaid on it I really like). He usually has a pair of black jeans and a pair of dark blue jeans that fit the "good" jeans category, until we order more, and then they are rotated into the regular jeans, and the new ones go to the "good" status. He cleans his boots off, no dress shoes here either.
I think I'd have a heart attack if I saw him in a suit. He had to wear a tux for my brother's wedding, and he looked horribly uncomfortable and out of place. I don't mind dressing up and getting all fancy, but it's not him. I'd rather he be comfortable in his clothes.
I've gone to semi formal weddings and events with him in his "nice jeans", and me dressed up, and have not had any comments or felt uncomfortable. The only time he looked "weird" was in that tux. He just couldn't carry himself confidently in a getup like that, unlike my brothers that were more used to dress up clothes.
(Yes, he was wearing jeans when we got married.)