Gamboge, rouge.
OGUE.
(As in "rogue"), rhymes vogue, prorogue, collogue,* disembogue. (As in "catalogue"), rhymes OG.
OH.
Oh, rhymes OW and OWE.
OICE.
Choice, voice, rejoice.
OID.
Void, avoid, devoid, asteroid, alkaloid, etc., and the preterites and participles of verbs in OY.
OIF.