1. Oracle of Ages
2. Link's Awakening
3. Oracle of Seasons
4. Minish Cap
5. Phantom Hourglass
6. Spirit Tracks
Ages was for me the best. The weapons were awesome. The rings were sweet. The sidequests were puzzling and engaging (not this pure collection crap in TP and probably SS). Seasons was great, but I didn't like the animals all that much, and changing between past and present seemed way more cool to me.
Link's Awakening was awesome. I'd use it as a bar of quality for handheld zelda games.
Minish Cap was lots of fun, but I never really felt that engaged in the story. To me it was too formulaic, but maybe that's because I had already played so much Zelda.
Phantom Hourglass was nice, but most of my enjoyment was from the new controls and such. It wore off and so did that one fucking dungeon.
I hated Spirit Tracks. Just more of the bad from PH with nothing good. IDK if I even finished it. I'm at the final boss, haven't even started the battle. Just didn't have the motivation. Maybe I'll try again when I'm back at school.