I agree collections of things is great at this age, we have tons of little characters of all different types and he loves all of them for imaginary play, lining them up etc. I wouldn't suggest playmobil at age 2yo though, but playmobil 123 is great as are little people, happyland people, and a whole range of TV characters, nursery rhyme characters (we have a set which either stand up or go on your finger as a little plastic puppet, loves them).
musical instruments, a keyboard, ukelele, recorder, harmonica, drum etc (I think we played music every day from 2yo to 3yo!)
duplo
kitchen, utensils and food (played with daily)
books - we got a fab set of 50 Mr Men books at least one was read every day for the entire year, he utterly loved them and still does.
play doh - mine likes tools, presses, cutters, extruders, the truck sets are really nice.
scooter (although mine still barely rides his but I see 2 - 3yos really getting into scootering)