Window shades - recommendations?

[Wallflower]

I'm starting to think about replacing the window shades that are in my house (all or at least most). Do you have any recommendations, warnings, suggestions, tips?

Thanks!

(Reasons to replace vary - in some rooms, they're a color matching the old paint/wallpaper. In other rooms, they're just old and a frustrating design. And I'm a little anal retentive and like things to match, at least in style (e.g., cords vs. no cords).)