Number one is spending time with a partner, once I find her. Then spending time with fellow hobbyists in things I am interested in, such as astronomy or the cat fancy. Then spending time with family, though we're spread out all over the southern half of the UK, so it doesn't happen very often.
I have almost zero interest in spending time with total strangers unless I have something in common with them (whether it is interests or personality type, in which case it can sometimes up to a point be enjoyable talking about each other's interests).
I absolutely detest smalltalk; life is too full of important things to talk about. For me, smalltalk is a means to an end; e.g., not offending people you care about but have nothing in common with, or not offending people you are forced to spend time with. In particular, at the beginning of a romantic relationship where the people involved like each other but are not yet sure how compatible they are with each other or how much to trust each other, so they begin with "safe" subjects for discussion.
Note that my reply focuses on who and what; the means is immaterial; though some means are more useful for some interactions than others, I will happily use face-to-face speaking, phone, internet chat, social media (both posts and PMs) and forums like this one; whatever best serves the task at hand.