It depends on the CPU you're getting, but in most cases, it doesn't make much of a difference. Unless you're getting an AMD APU, DDR3-1600 is perfectly fine.
Also, whats the differance between regular ram and G.skill, or Vengeance? Is it just looks?
Just to dispel any confusion, G.Skill or Corsair RAM is regular RAM. If by "regular RAM" you meant DIMMs that don't have heat sinks on (such as http://brain.pan.e-merchant.com/1/9/19713391/l_19713391.jpg), then the only difference between those and DIMMs that do have heat sinks on is... the heat sink. In the end, very few of those RAM brands actually make RAM, in most cases they just buy it from the companies that do make RAM (e.g. Samsung, Micron, Hynix, Elpida, etc.)
-What is best in life? -To crush your enemies, see them driven before you, and to hear the lamentation of the women.