For a tricycle, I like the Schwinn Roadster. It's low to the ground so it's hard to tip over. I have twins and one picked the Schwinn Roadster and one picked a more classic style tricycle. The one in the classic style trike has tipped it over multiple times by turning too tight.
Here is a link to the Schwinn Roadster, which also comes in blue:
http://www.toysrus.com/product/index.jsp?productId=376471...
For bicycles, I've heard a lot of people having good luck by starting with a balance bike. They are small and light. If you get one with an adjustable seat it will grow with the child some, but eventually, you will want to switch to a pedal bike. The goal with the balance bikes is to skip the training wheels phase.