It's a trial and error thing. You have to collect various types (arboreals, terrestrials, burrowers, old world, new world, etc) until you find out exactly what you like/dislike.
I would say, collect at least one of each of the following:
Poecilotheria sp.
Avicularia sp.
Lasiodora sp.
Brachypelma sp.
C.cyaneopubescens
Hysterocrates sp. or M.balfouri
Acanthoscurria sp.
S. calceatum or H.maculata
Grammostola sp.
Dwarf species
as you grow into the hobby, you'll also develop "tastes" in certain species. E.g. I don't like Avicularia sp. - I only have one and if she dies of old age, then I doubt I would replace her. I also don't like the dwarf species. Some people prefer Old world species, others prefer new world species.
So my philosophy is: Try everything at least once