Some of the main proposals have been:
- Mneme - Richard Semon, 1921;
- Gene - George Williams, 1966;
- Replicator - Richard Dawkins, 1976;
- Codex - George Williams, 1992;
- Sign - Terrance Deacon, 1999;
- Reproducer - Jim Griesemer, 2000;
- Meme - Evan Louis Sheehan, 2006;
"Reproducer" is OK, but it seems a bit vague.
"Meme" and "gene" seem as though they are fighting with historical usage a little.
"Mneme" is too hard to pronounce.
The umbrella term is probably more important than any particular sub-category.
My vote goes to "gene", from G. C. Williams, 1966.
My vote for second place goes to "reme" - my proposed replacement for "replicator" / "reproducer" within the domain of gene/meme terminology.