Some most excellent Yiddish (or possibly Yinglish?) words to be employed in polite and not so polite conversation
bubbeleh honey/dear/pet
bupkiss nothing
chotchkeh knick-knack
chutzpah insolence or cheek
faklempt bummed out, bad mood; also choked up, emotional
farkatke lousy, ridiculous
goy non-Jew
kvetch complainer, bitcher
mensch real man
meshuggeneh mad or crazy
mishigas craziness
nebbish a man who walks into an empty room and it's still empty
putz jerk or stupid ass
schadchn matchmaker (female)
schmuck dirty penis (so use this word with care...)
schnorrer moocher, beggar
shiksa goy female (male=sheygets)
shlemozzel uproar
shlemiel clumsy person, pitiful bungler, fool
shlep drag or carry; long journey; stupid oaf
shloompy frumpy or slovenly
shmaltz extreme sentimentality
shpilkes nerves, nervous energy
shtick theatrical routine
shtup shag or screw
schvitz to sweat
veys mir oooooooooh my god (also oy vey, vey gevalt)
yenta gossip
Also check out A Goy's Guide to Yiddish and the Yiddish-English/English-Yiddish Online Dictionary