Easy!
great (gr t)
adj. great·er, great·est
1. Very large in size.
2. Larger in size than others of the same kind.
3. Large in quantity or number: A great throng awaited us. See Synonyms at large.
4. Extensive in time or distance: a great delay.
5. Remarkable or outstanding in magnitude, degree, or extent: a great crisis.
6. Of outstanding significance or importance: a great work of art.
7. Chief or principal: the great house on the estate.
8. Superior in quality or character; noble: "For he was great, ere fortune made him so" (John Dryden).
9. Powerful; influential: one of the great nations of the West.
10. Eminent; distinguished: a great leader.
11. Grand; aristocratic.
12. Informal Enthusiastic: a great lover of music.
13. Informal Very skillful: great at algebra.
14. Informal Very good; first-rate: We had a great time at the dance.
15. Being one generation removed from the relative specified. Often used in combination: a great-granddaughter.
16. Archaic Pregnant.
n.
Bearing in mind definition 16, is an SM58 a "great" SM57?
Seriously, the SM57 is a very useful mic and everybody should have a few in their mic box.
However, if I was going to limit myself to a single mic, would it be an SM57? Nope. I can name a ton of mics I'd rather have in that situation. My personal favourite (useless in this discussion since you can't buy them anymore) is the original C451 with removable head. I use them for almost everything and worry for the day when I have to try and replace them due to age.