I think there's less enthusiasm for the 500 homerun Mark since the number of people who've done it has nearly doubled in our lifetime.
I don't disagree with this, but I'm sure it was more exciting than whatever was happening on a Tuesday night at the bar Deathfromabove was hanging out in.
It feels like one of those things that's a much bigger deal if it's one of "your guys."
Obviously, I'm not a casual baseball fan. I watch more than just my team (I actually had the Braves-Marlins game on in my office this morning and am listening to Tex-Oak right now), and have a text chain of baseball fans where we let the others know when something unusual is happening (no-hitters through 6, chances at cycle, etc.). I go out of my way to see milestones (I saw Palmiero's 300th and 400th, the 3000th hits of Palmiero and Brett, and Reggie's 500th). I get pretty fired up fir this stuff whether it's my guy or not.
I've seen a number of one hitters in person, and agree with Hutch, that no-hitters are pretty damn exciting. The most frustrating one for me was where Mark Kotsay lead of the game with a double, and John Lackey retired the next 27 guys. Really? One batter from a perfect game, and you don't even get to enjoy the excitement? Orlando Cabrera snapped a 63 game reaching base safely streak that night too - at the time like the 5th or 6th longest in history or something.