Since there are several hundred genera of ornamental grasses and countless more species and hybrids, it would be a pretty long list :-) Most good ornamental grass references will call out this distinction. I particularly like Rick Darke's "Encyclopedia of Ornamental Grasses" but there are other good references as well.

Maybe we should build our own list. Of all the genera of grasses, sedges and such, a list of popularly cultivated ones would be much shorter.

I've been making one as I read about and/or grow various grasses. Please feel free to add/correct, and I'll compile.

Cool Season

Achnatherum
Anthoxanthum odoratum
Briza
Calamagrostis arundinacea
Calamagrostis epigejos
Calamagrostis foliosa
Calamagrostis nutkaensis
Calamagrostis x acutiflora
Carex grayi
Carex muskingumensis
Deschampsia
Elegia
Festuca
Helictotrichon
Hystrix patula
Luzula
Melica
Milleum
Nassella tenuissima
Sesleria
Stipa capillata

Warm Season

Ammophila
Andropogon
Arundo
Bothriochloa
Bouteloua
Buchloe
Calamagrostis brachytrica
Chasmanthium latifolium
Cortaderia selloana
Cyperus
Eragrostis spectabilis
Lagurus ovatus
Miscanthus
Panicum virgatum
Pennisetum
Saccharum ravennae
Setaria faberi
Tridens flavus