Looking back at notes and photos, I see DS used to enjoy:
- baby swim classes. We started about this age and they were great fun. (We stopped a few months later because I went back to work, so he didn't get long-term learning to swim out of it, though!)
- playgrounds: it was about this time that he started to love swinging, and he also liked the whole experience, watching the other kids, etc.
- books, especially ones with thick, easy-to-turn board pages he could manage himself. He had a few (Spot, I remember, for example) that had textures on the pages and/or musical bits, and they were favourites.
- he had a couple of wooden pull-along toys that he loved starting around this age and going on for years... googles... yes, this one is a good candidate for best value toy we every owned, as it got used in so many ways for so many years (still, occasionally):
http://www.kazootoys.com/haba-convoi-stacking-blocks.html- he had a musical mobile with several buttons to e.g. choose which of 3 tunes to play, and he learned to operate it at around this age. That was definitely a mixed blessing, though - if you get such a toy check it has music that doesn't grate within the first 10,000 repetitions...
Have fun!