I have an Ivory Timex Expedition with a black nylon NATO strap and it's perfect for me. It's understated and simple. It's very functional. I wear it everywhere except when swimming or if I have a critical meeting the next morning and want a backup alarm on my watch. I have a digital Marathon for those reasons, but I miss my Expedition when I wear it.

I think the Expedition can be worn with casual clothes or dress clothes. The NATO nylon strap isn't the greatest when I'm in a suit, but it's black so it's not too noticable. I'm not a fan of leather or steel straps so I'm not changing it.