I've ranked all 24 masks from most to least useful:

1) Goron Mask
2) Deku Mask
3) Zora Mask (I put these three as the top three because they're necessary for beating the game)
4) Great Fairy Mask (only because some fairies, and hence items, are impossible without it)
5) Bunny Hood
6) Blast Mask
7) Stone Mask
8) Fierce Deity Mask
9) Mask of Truth
10) Romani's Mask
11) Mask of Scents
12) Gibdo Mask
13) Captain's Hat
14) Garo's Mask
15) Postman's Hat
16) Bremen Mask
17) Kamaro's Mask
18) Don Gero's Mask
19) Keaton Mask
20) Circus Leader's Mask
21) Kafei's Mask
22) Giant's Mask
23) All-Night Mask
24) Couple's Mask

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Belief or disbelief rests with you. To die without leaving a corpse... that is the way of us Garo
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