It's precisely as MackleDoge says. Your ruin build should be individual to the champion you're playing. You can't use one build for all your top lane champions as you can't use the same masteries for all your champions.
Generally speaking though, if you're going a tanky champion like renekton or shyvana, you'd want Flat armor yellows, flat/scaling mr blues (up to you), and considering the fact that you, as a tank, are going to build armor and hp, you don't really need those armor reds and or hp quints. So what I usually do is go flat AD reds and flat AD quints for that extra damage early. Life steal quints are only viable to certain champions such as Nasus. If you're playing tryndamere however I'd suggest attack speed quints, yellows and armor pene reds as well as flat mr blues.