Mega Bloks are also a good gift for that age, and mom and dad can have fun too. My kids have a couple thousand of them, and they don't fall down as easily as the flat edged wooded blocks. They also love sticker books, or stickers of any kind. My son loved this around that age: Fisher-Price Little People Lil Pirate Ship, depends what he is into.
Board books and the time to read them with him. My son also started loving Thomas and Friends around that age (he still does). Also around that age I got him a Green Toys Dump Truck which is still one of his favorite toys (he's almost three now). In another six months if you want something really nice I'd say a Strider balance bike and helmet but only if someone has the time and energy to go out with him with it on a regular basis. This bike gives me (dad) as much exercise as my son these days, I have to run (not jog) to keep up with him now. For educational toys Leap Frog makes some good things, and their videos are very good too.
My kids loved these and even 9 years later still enjoy getting them out to build houses and forts with. Melissa & Doug 24 Pc Basic Cardboard Blocks They also liked the wooden blocks mentioned above and often use both for their creations.
Duplos, Sand/Water Activity Table, Small table for indoors where they can do their own crafts, Playhut tunnel/tent for crawling and hiding, any Little People set, ride on toy, love the cardboard blocks as well....btw...I am a mother of four (13, 18, 24, 25)...we have owned every toy on the planet.
Any board books, even if just pictures. / Any sit to stand type of table [music and lights are cool... but really wonder how much they contribute to our kids attention span these dayz :/ ] / edushape toys are on sale / discovery toys are also good for developmental or educational type of toys... blocks. Nothing to flashy or fancy is really necessary. I mean, they do have the rest of their life still! lol