True 50MB PS2 games are rare unless they are simple 2D titles or extremely stripped "rips." However, several high-quality games are known to compress into very small packages:
A fast-paced arena fighter where the core gameplay remains intact. ~150-200 MB Highly rated aerial combat that is naturally small in size. The Red Star ~200-300 MB A high-quality "shmup" (shoot 'em up) that is lightweight. Half-Life
For legitimate archival copies, community consensus often points toward verified dumps on Archive.org rather than "highly compressed" spam sites.
: Another title frequently cited in compression lists for maintaining playability at a low file size.