Make your argument!
Mine: Playstation 2
*With an exceptional library that covers just about everything, it's not hard to find several games worth playing regardless of what dictates to you what is worth playing. I'd argue no system has a library better in wide range and quality than Playstation 2. You have compilations from older systems from Atari to Sega Genesis with titles like the Activision Anthology, Taito classics, Sega Genesis Collection, Mega Man Collections and more. Survival horror? Yeah we got several Silent Hill releases, Resident Evil releases and lesser known titles like the X-files game, Clock Tower 3, Cold Fear and others. Light gun games? How 'bout access to 4 Time Crisis games, Resident Evil Dead Aim, End Game, and Dino Crisis. RPGs? Like 10 Final Fantasy releases, Castlevania, and many more. Several fighter games like the DBZ boudokai and Mortal Kombat series. Open world/sandbox games like 3 GTA games, Gun and many more. Stealth games from Tom Clancey to Hitman. God of War I and II, sports games, the list is nearly endless. This system literally had several games in each genre that were all worth owning then and now. This system has a plurality of games that are worth buying the system for and not the other way around.
*It had backwards compatibility like all systems really should. It even carried over to hardware. Sony kept the same controller design from PS1 because it made sense. There really isn't anything wrong with that controller at all. How many times have we been annoyed with a controller change with the next generation of consoles? That didn't happen here.
*It was fantastically received by consumers (150M+ consoles sold), which means the secondary market is affordable now.
*It had beautiful graphics that are still as vibrant and in some cases (see: God of War series or Shadow of the Colossus specifically) still awe inspiring.
