I'm trying to remember back to that age...I think his favorites were the Fisher Price Farm (still loves it today), the Baby Mozart Cube, and all of the stuffed animals on his play yard.
DS LOVED anything that made noise and had lights. I know that babiesrus/toysrus is having a sale currently on some of the brands that are buy one get one free. He still loves this from fisher price.
Re: New toy ideas
DS is Obsessed with this recent purchase, though i think he would have enjoyed it a month or two ago just as much...
Sorry cant linky it but if you google HABBA frog you will find it.