i'd start with Pink as well (ditto on "Blackout," absolutely essential song — but what really does it for me is "Just Abandoned Myself," best song they've ever done!).
after Pink, if you like it, think about it:
- if you like "Farewell" and "My Machine" best, try Soundtrack from Mabuta no Ura, Attention Please, the last half of Smile (especially the Japanese mix), maybe Altar, Rainbow, New Album and the Japanese Heavy Rock Hits singles
- if you like "Pink" and the other fast songs best, try Heavy Rocks (1 & 2), Smile (the Southern Lord version), Akuma no Uta, Vein (hardcore version)
- if you like "Blackout" best, try the drone/stoner stuff: Absolutego, Flood, Feedbacker, Amplifier Worship, Dronevil, The Thing That Solomon Overlooked 1-3, Klatter, Vein (drone version), some of the Merzbow & Michio Kurihara collabs
it's a rough breakdown, but it sorta works.
another easy method is the album Variations, which a compilation is designed for newcomers interested in the Pink-style fuzz-rock-stoner-metal thing. notable for containing the best recording (imo) of the song "a bao a qu," one of their finest hours.