The difference is the "better" colleges are more selective. When the majority of your students are the brightest and most motivated, they should also be successful after they graduate. I'm not sure how much I attribute it towards the quality of education. The degree from those schools is basically an advertisement to potential employers that you're a bright and motivated person.
On the flip side, most big state schools are less selective and give potentially less motivated students a chance to turn things around. Many of those people do and are very successful after college.
I really don't think it matters after you've worked for a few years, have a resume and have built a reputation.