English is regularly singled out for the size of its vocabulary, but it's often struck me that there are some conspicuous gaps. Despite the varied means of wordsmithing in English and the creativity of its speakers, there seem to be fewer words for different types of people than in other languages I'm familiar with, such as French, Korean, or Irish. Moreover, those words which do exist often sound childish or slangy rather than simply informal or colloquial.
So here's my attempt to make a list of common terms for people who are characterised by certain behaviours or personality traits. It's of necessity rather Americocentric, so I encourage speakers of other varieties to make additions and suggestions. My rule of thumb for terms derived from proper names is "Would a speaker understand a term without necessarily getting the reference?" (That is, I think the average English-speaker knows what an "Einstein" or a "Pollyanna" is whether or not they could tell who was Albert Einstein or Eleanor H. Porter.)
bore
busybody
cassandra
Chicken Little
class clown/cut-up
coward/fraidy cat/scaredy cat
crusader
egghead/intellectual
Einstein/genius
fussbudget
geek/nerd/grind/pointdexter
jobsworth
jock
lazybones/layabout
liar
mallingerer
martyr
narcissist
nervous nelly
petty tyrant/little dictator
pollyanna
prude
psychic vampire
schoolmarm
shirker/malingerer
slag/slut
slob
slowpoke/slowcoach
snoop
snitch/tattletale
social butterfly
stoner/pothead
wimp/wuss
womaniser
worrywart