The first smell of freshly cut grass
The first whiff of a hyacinth, or lilac, or lily of the valley
The first time you can take your shoes off again walking the beach
I'm also a little hesitant to move into spring because we didn't really have a winter here in Chicago, so much of my winter list did not get accomplished. No sledding, sadly, and no ice skating. The latter could have been accomplished, of course, because the ice rinks were open, but I just never really got into that full winter mode.
Anyway, I'd love to hear if you have things you like to do in spring, perhaps it's your favorite season and you have a whole long list. Here's my spring list for now, but please bring on ideas!