Stefan Hattenbach's New Global, Barry Deck's Traitor, and Joe Kral's Wrongway are sans with slap on serifs.

T-26 unleashed a string of sorry attempts at this theme, such as Equipoize Serif, Andromeda, Amplifier, Regeneration X, Deux, and Missive. But Time In Hell is better.

Dennis Delude's Tex Loose

Pilgram

RXC's Alembic

Morphica

Cheltenham!

Letters that are usually sans serif, even in serif typefaces:

O, e, g, o, t.

Figures:

4, 6, 8, 9, 0

Agfa Rotis Semi-Serif

---------------------------------------------
Yes, I'm old, but I'm back in style!

The Mix.

***

Monowidth sans faces often have serifed I, i, j, and l

***

>Cheltanham

David, you can now edit your posts after they're in the thread -- brilliant new Typophile feature!

the T-26 ones may not be masterpieces, but Iike Missive and maybe Andromeda.

Coda, a monospaced grayscale pixelfont, in development...
It uses semi-serifs to improve spacing, not for frills.

hhp

Max Kisman's FF Fudoni

Christopher Kalscheuer's FF Maverick

Eric Lin's Tema Cantante

Yanek Iontef's Case Sera Sera

Sibylle Schlaich's Styletti

It's really cool how Missive has serifs on the "o".
It actually makes a quite legible text face.

Of course, a lot of those faces are pretty dodgy regarding "point piracy".

This thread would be so good if all the fonts referenced were actually visible in it.
Links are OK, but comparative specimens would be better.
When's it gonna happen??!!

Maybe I'll post them all in a Typographica article.

Don't forget Entropy from T-26.

My list includes only typefaces which were constructed/assembled using the forms of existing typefaces (whether actual digital data or redesigned from scratch).
So original designs like Alembic, Equipoize, Rotis, Maverick, Tema Cantante Traitor or Morphica (which I consider different) are not listed.

Please forgive my not providing links. I'm in a hurry, but I wished to share this list. This is a selection of what I considered more interesting, or which appeared first. Many of them are already "historical". I did a lot of these lists while I was collecting information on the digital revolution in typography.
This one was called "Type Surgery"
If you have other examples you consider worthy, I will add them.

2RebelsUn (2 Rebels)
Addmorph (Brian Schorn at Cranbrook, used in Ray Gun)
BirthRiot (Sacred Nipple)
Canadian Photographer (GarageFonts)
CaseSeraSera (Apply Design)
Entropy (T26)
Fudoni (Max Kisman/FontShop)
Futile (GarageFonts)
Hegemonic (GarageFonts)
International Disgrace (GarageFonts)
Konflikt (Linotype)
Missive (T26)
Nameless (2 Rebels)
Neo (T26)
Not Caslon (Emigre)
Osprey (T26)
Prototype (Virus)
Razzia (2 Rebels)
Sacred Cow (David Shields at Cranbrook, used in Ray Gun)
Tex (2 Rebels)
The Royal Family (Thirstype)
Time in Hell (T26)
Zanzibar (Fountain)

Please note that Stephen Farrell's Missive is unique in that selection, since it uses parts of a Garamond, and parts of an earlier beta of Barry Deck's Arbitrary. An historical design collaged with a post-structural, almost contemporary one. It actually does not work so good in text, but the use of classic proportions (the Garamond-like Os) introduced an element of interest.

Once I designed a set of oldstyle numerals for it, although I never used it.

I recall (although memory not always reliable) that FontHaus published a large format magazine a while back with a page that used Missive as a text face, and it looked highly legible, even with, or perhaps because of, the serif on the "o". But perhaps the readability was a result of the inherently virtuous metrics and color of the constituent "parents".

Wasn't it also used in the US for a major credit card campaign?