Rune Choices

So far, I look at most people's rune pages and most of them follow the same general guidelines in terms of what they are. For an AP page I generally see magic pen reds, armor yellows, MR blues, and AP quints, and for an AD page you instead have AD reds and AS quints. However, I've lately been wondering on how efficient these defensive runes are for any rune page because it seems they are falling off in effect compared to other runes that are slowly rising in sale, such as CDR/lvl blues or HP/lvl yellows. I'm really debating on what to use for a general rune page.

What do you guys think I should use for yellows and blues?