Warded to the OrderSaid I was going to do this, so here goes. Took the ones I remember - probably missing some. Input and proof is good. I'll update as you tell me more.
Confirmed Death EatersDieter Lestrange
Fenrir Greyback - in league; was seen with them
Murdoch McTavish
Virgil Jugson
Benedict Avery
Probable Death Eaters - reason
Rabastan Lestrange - son of confirmed; Purist opinions; on Gamp list
Rodolphus Lestrange - son of confirmed; Purist opinions;left Nott wedding (pre-Hogsmeade attack) and Black party (NYE attack) early; on Gamp list
Bellatrix Lestrange - daughter in law of confirmed; Purist opinions; left Nott wedding (pre-Hogsmeade attack) and Black party (NYE attack) early; on Gamp list
Filbert Mulciber - Purist; son is very probable; apple doesn't fall far.
Xander Mulciber - son of Filbert; Dark Magic user; threats against Muggleborns; knows something about recent attacks; left Nott wedding (pre-Hogsmeade attack) and Black party (NYE attack) early
Severus Snape - friends with Mulciber, half-blood; likely attacked S. Black
Elliot Avery - son of confirmed, 'self-absorbed snot'
Possible Death Eaters - reason
Vivianne Avery - Purist opinions; left Nott wedding (pre-Hogsmeade attack) and Black party (NYE attack) early
Alecto Carrow - friend of Lestrange boys; Purist opinions; possibly in Hogsmeade vs. Black
Amycus Carrow - friend of Lestrange boys; Purist opinions
Antonin Dolohov - Purist opinions; friend of Lestrange
Walden Macnair - Purist opinions; left Black party (NYE attack) early
Marion Macnair - left Black party (NYE attack) early
Lucius Malfoy - Purist opinions; brother-in-law of Lestranges; left Black party (NYE attack) early
Narcissa Malfoy - Purist opinions; sister and -in-law of suspects; left Black party (NYE attack) early
Augustus Meliflua - Purist opinions
Araminta Meliflua - Purist opinions
Junia Meliflua - Purist opinions; threatened MacDonald
Julia Meliflua - sister of above
Tennyson Nott - Purist opinions; friend of Lestrange
Lucian Rosier - Purist opinions; friend of Lestrange
Evan Rosier - son of suspect; left Black party (NYE attack) early
Rita Skeeter - Purist opinions; friend of Lestranges
Charlemagne Travers - friend of Lestrange boys; healer; left Black party (NYE attack) early
Lettie Travers - wife of Charlemagne; left Black party (NYE attack) early; extremely injured at Nutcracker attack - mistake? punishment for attending the ballet?
So, what else do we know about these people? Who's missing from the list? Rather you mention someone you're unsure of than leave someone off that turns out to be a Death Eater.
Update: (Nov. 4, 1978) Reorganized a bit. New categories. To move from Possible to Probable some sort of proof needs to be given. To move from Probable to Confirmed, we need a sighting in a mask, etc.
Update: (Jan. 2, 1979) Added info from Nutcracker, NYE. Reorganized a bit more.
Update: (Jan. 20, 1979) Added Greyback to confirmed; Added Lestrange info re: Gamp list.
Update: (April 10, 1979) Added McTavish and Jugson to confirmed.
Update: (Apr. 14, 1979) Added Avery to confirmed.