Surprised there aren't more comments on this show.... I agree with some of Logos's typings. Here goes...
Michael: LIE (the boring workaholic who always does the right thing)
Lindsay: SEE (this one should be obvious. Image concerned, materialistic.)
GOB: EIE (not sure why people are saying SLE - he's super-dramatic. Thinks Michael should have more fun.)
George-Michael: LII (I think Michael Cera is LII also. Definitely some
type and seems too serious to be
leading. Character seems to share
values with GOB.)
Maeby: SLE (the troublemaker - might consider LSI or ILE too. Not too sure about this one, really.)
Buster: EII or IEE (Infantile to Lucille's Caregiver)
Tobias: IEE? Some NF. I think Cross is probably Delta NF. Maybe IEI works.
George Sr.: SLE or LSI (womanizing, amoral, but also suave and shrewd. Rather close with GOB - maybe LSI is better.)
Lucille: SLI (I can see why you would think she's an
type, but she actually uses
a lot. Plus her relationship with Buster as pointed out above. Doesn't respect Michael much at all, and really hates GOB. Kind of likes Lindsay and really likes Buster - all the relationships work out perfectly.)