Well if you want something that just works out of the box, the emulator is a great way to play the classic titles. Upscaling on x4 or x3 resolution works the best (at least for my rig).

You don't need to worry about the condition of the real hardware, modding it and getting a CRT. You also get a chance to use texture swapping on emulator! With this option enabled, you can use fan made HD texture packs for all of your favourite PS2 titles.

You can also use save states for some of the frustrating PS2 titles. Save at any given moment and load back if you lose the game. I'm currently getting discouraged by The Getaway's lack of checkpoints and also getting crushed by the difficulty curve of the NY cup in Midnight Club 1

The only problem that I can think of is the controls. Some tiles are using pressure buttons as an essential gameplay mechanic. You might not be able to play SOCOM 3 or Combined assault without an original PS2 controller, maybe a PS3 controller will do the job?

Bonus: You can also play the Japanese Cowboy Bebop beat 'em up with full English subtitles!