How many PS3 games actually use the Blu Ray storage?

[FelmanX]

FinalEvangelion said:
Lost Odyssey uses 4 DVDs, Xenosaga II also came on two DVDs. They are out there.

@Cryoakira, Uncharted actually didn't use the HDD. But yeah, there were no load times.

 didn't it cache data to the hard drive?