Kodachrome
They give us those nice bright colors
They give us the greens of summers
Makes you think all the world’s a sunny day,
Oh yeah I got a Nikon Pentax camera
I love to take a photograph
So mama don’t take my Kodachrome away
KODACHROME (K64) was slow, but it has this most distinctive and pleasant colour palette, and on the occasions when I shot 35mm slide film (a Pentax LX was my prime 35mm DSLR) I preferred it to Fuji Provia or Velvia (the old Velvia was ISO50, which was even slower than K64.)
Because of the thick film base, K64 was also a real pain to scan into electronic format until a few years ago when affordable 35mm film scanners became good enough, but K64 was already on the decline then.
Which reminds, me, I’d need to find a custom curve simulating K64 for my Nikon D300.