My favourite Digimon game! Aside from the weird glitches (e.g. jukebox), it was perfect to me. I played it a few times on ePSXe emulator (never owned a console ), though I don't recall ever winning the game.
I remember grinding my Agumon to fight Goburimon in order to make him learn magma bomb, because it was necessary to digivolve into Greymon. Fun times.

DW1 is the best for me because of its non linear gameplay. I remember the game doesn't force you to do missions in certain order. There are also side quests.

One I remember is the tournament that you can only enter if your digimon is insect type. The only way to get an insect digimon is to sleep besides a certain bush while in training level, and your digimon will evolve into Kunemon, then Kabuterimon.