It seems that as the years go by on Newgrounds, animations only seems to become of higher quality. This isn't to say that older flashes aren't as funny or are inferior, just the technology wasn't available to produce what we have now.
Anyway, I've been doing some thinking, and it seems you could classify Newgrounds into 3 distinctive eras.
The Early Years- Most notable for submissions by Tom Fulp, Dan Paladin, and the emergence of the clock crew. Also saw the beginning of the madness series.
Eventually, the animation improved and action scripting became more advanced, beginning the next era. I'll name it for the emergence of what is probably the most famous submission of the time, the Numa era. Notable Authors of the time include Legendary Frog, the Super Flash Bros., Piconjo, as well as sprite animators, such as Randy Simms, and Bigfoot. Notable games include the Newgrounds simulator and the rise of dating sims. This time also marked the beginning of the brackenwood series, which is still well above the level of most of the best animators today.
The most recent era, which I call the Modern era, has seen a great improvement in animation quality as well as more advanced games. The stars of this era include Micheal Swaine, Egoraptor, HotDiggityDemon, UkinJoe, and Chris O'Neil. During this time, flashes are becoming more or less like professionally produced cartoons.
Certain artists have transcended these eras, such as Tom Fulp, Krinkels, and Adam Phillips.
Anyway, what do you think Newgrounds? This is all just speculation on my part, but I thought I'd share it.