depends on how you define completed. like 100%, did all side stuff, etc? almost none.
snes:
final fantasy 6
chrono trigger
secret of mana
legend of zelda: link to the past
playstation:
final fantasy 7
final fantasy 8
final fantasy 9
ps2:
final fantasy 10
final fantasy 10-2
final fantasy 12
dark cloud 2
kingdom hearts
kingdom hearts 2
katamari
we <3 katamari
(probably some others that i can't remember)
okami
ps3:
flower
flow
little big planet
wii:
elebits
super mario galaxy (beat this before it was even released

)
super paper mario
cooking mama (got gold on all recipes. does that count as beating?)
okami
probably some others that i can't remember
psp:
patapon
patapon 2
ds:
final fantasy tactics a2 grimoire of the rift
drawn to life
etrian odyssey
pokemanz diamond
(too many others that i can't remember. M3 ftw)
xbox 360:
portal (both orange box and still alive)
assassin's creed
beautiful katamari
eternal sonata
i've probably forgotten some.