So our objective is to build the coolest RPG system ever, basically.

Seems like a good starting point is to make a list of things we like about other games we've played.

Things that are cool or desirable, in my opinion.

• Using variously-sided polyhedral dice (still makes D&D fun).
  
• Giving characters background, like previous professions (as in Traveller, or Call of Cthulhu).
  
• Giving characters advantages and disadvantages (like GURPS).
  
• Simple skill systems (like CarWars).
  
• In character generation, a balance between randomness and planning; we want to avoid either extremes of "keep rolling until you get something you like", as in D&D, or "designing a character like a CarWars vehicle", as in GURPS.
  
• The less you have to read the rulebook, the better. Ideally almost everything you need to know while playing should fit on a cheatsheet.

Got an opinion? By all means leave a comment!