DS is 19 months and loves his cars at the mo, he's got a thomas starter set (my bargin of the week - 6.99 in woolies!)
walker/ride on toys - DS had his first one before he could walk proeprly and it really helped him,
failing that i'm suggesting family get little people if they choose to get him things, or building blocks, aqua draws I hear are good, and also a little kitchen (If I can find one reasonable enough! lol) with pots to go with it - hours of fun.
also going to get a feew boxes - not being a scrooge but he's really into climbing in them rihgt now!