I can't choose one either - but I looove hot fudge -- ok, I'll go vote for that. Chocolate jimmies are awesome too. So good.
But this is what I like to do: Warm up some peanut butter in the microwave, add frozen yogurt (it melts a little faster b/c of the heat), chocolate syrup, strawberries and some whipped cream and a broken up cookie. YUM. Must eat with lots of water though.
When my sister and I were kids and used to have a bowl of ice cream, we would stir and stir and stir it and try and wait until it melted - awesome.