What is the best Scooter for my 4 year old?

Should I choose one that has 2 wheels on the back or 2 wheels at the front? He is just turning 4, and loves to see the big kids with their razor scooters.

My sister bought my son a 3-wheeled scooter that had 2 wheels on back and one on front...he loves it. She got it at Target for about $20.

I think the scooter chould be 2 wheels on the front and 2 wheels on the back!
you can get that at Toys-R-Us or Target.