It is certainly known that the discoveries of some objects may be disputed and thus the list modified. Note we take NGC 5866 as M102.
Ordered by score, the original discoverers of the Messier Objects are:
Discoverer Score Objects
Al Sufi 1 31 Aratus [44] Aristotle [39?][41] Bevis 1+1 1 (35) Bode 5 53 64 81 82 92 Cassini GD [50] Cysatus +1 (42) Darquier 1 57 De Cheseaux 6+1 4 (6) 16 17 25 35 71 De Mairan 1 43 Flamsteed +1 [8] (41) Halley 1 13 Herschel C +2 (48)(110) Herschel W +9 (47) (91)(102)(104)(105)(106)(107)(108)(109) Hesiod 1 45 Hevelius [40] Hipparchus 1 44 Hodierna 8+1 6 33 34 36 37 38 41 (42) 47 Huygens +1 (42) Ihle 1 22 Kirch 2 5 11 Koehler 3+3 59 60 67 (71) (81) (82) Lacaille 3+3 (4) (6) (7) 55 69 83 Le Gentil 2+2 8 32 (36) (38) Maraldi 2 2 15 Marius +1 (31) Mechain 28+4 63 65 66 68 (71) 72 74 75 76 77 78 79 (80) (81) (82) 85 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 Messier 40+20 (1) (2) 3 (5) 9 10 12 14 (16) (17) 18 19 20 21 23 24 (25) 26 27 28 29 30 (33) (34) (35) (37) 39 40 46 (47) 48 49 50 51 52 (53) 54 56 (57) 58 (59) (60) (61) 62 (64) (67) 70 73 80 84 86 87 88 89 90 91 (92) 93 (102) 110 Oriani 1+1 (60) 61 Peiresc 1 42 Ptolemy 1 7
Total 110
Messier (40), Mechain (28), Hodierna (8), De Cheseaux (6), Bode (5), Koehler and Lacaille (3 each), Kirch, Le Gentil and Maraldi (2 each), and Al Sufi, Bevis, Darquier, De Mairan, Halley, Hesiod, Hipparchus, Ihle, Oriani, Peiresc and Ptolemy (1 each).
Independent discoveries, including co-discoveries, of Messier Objects lead to the following ranking:
Messier (60), Mechain (32), William Herschel and Hodierna (9), De Cheseaux (7), Koehler and Lacaille (6 each), Bode (5), Le Gentil (4), Bevis, Caroline Herschel, Kirch, Maraldi and Oriani (2 each), and Al Sufi, Cysatus, Darquier, De Mairan, Flamsteed, Halley, Hesiod, Hipparchus, Huygens, Ihle, Marius, Peiresc and Ptolemy (1 each).