There is a personal top 5 or 10 and then there are the top lists where you try and take your own personal bias out of the equation. For example Ras Kass is one of my favorite MC's but I wouldn't argue that he's a top 10 MC because I know that there are many more artists who have just as much skill as he might have on the mic but have made better records, contributed more to the culture, etc. To me KRS & Rakim are always in that top MC ever discussion much like Jordan and Magic have to be in the top 5 if you're talking basketball players. Forget age or when you heard them or what you grew up on..I love MC's from all different eras but I have never heard anyone display better skills on the mic than those 2. For some reason Hip Hop is the only genre I can think of that some people feel like you have to have been of a certain age to acknowledge the greatness of an artist. If someone were to ask me to give them examples of MCing at it's finest I'd take a song from Ra and a song from Kris to show them that this is the best I've ever heard.