Best years for ROH?

I've been paying for HonorClub and only catching the weekly show until this previous weekend, where I started watching old matches since I never really watched it until TK bought the promotion.

What are the best years to go back and watch first? I'm intending on going through the full years, but individual matches/events are good to suggest too! I like the Elite and all that, but would love to see Steen and El Generico and the others that have moved onto WWE since being in ROH, as well.

Looking forward to hearing everyone's suggestions!