Sticking to the actual thread, I love both, but I voted for Destiny.
As respect77 said, Triumph is OTW part 2, and no MJ album collection would be complete without this transitional release from OTW to Thriller. It's a fantastic little album, it has the funk and danceability of OTW, but also the drama and theatrics that were to follow with Thriller. Walk Right Now and Heartbreak Hotel are two of MJ's finest tracks, with or without The Jacksons imo. I always wished MJ would've done Walk Right Now on the Bad tour instead of Lovely One.
But for me, Destiny wins the race, mainly because it's his most confessional album alongside HIStory. You have the great funky dance grooves of Shake Your Body, Things I Do For You and All Night Dancin, but it's the ballads that are the heart and soul of this album. There's just something very special about songs like Bless His Soul, Push Me Away and That's What You Get (For Being Polite). It is an album of growing pains and familial frustration. It is the first time MJ sounds as if he is singing about something which he has actually lived and you can tell he really poured out his heart on this album.