Intelivision/atari2600 to NES was amazing. No more single rooms, you could go down pipes and open doors. It was like every game was pitfall x100 (atari's one scrolling adventure game). More colors better graphics was great and then Zelda... Final fantasy, wizards and warriors, castlevania, dragon warrior, smb. Duck hunt, zapper, etc.. Nothing like it. The fact that $99 got you the console two controllers, a zapper and both smb1 and duck hunt. You don't get value like that now.
Next was going from nes to Tg16, was amazing. The extra colors the larger sprites, no flickering. Alien and Devils crush along with blazing lasers are amazing to this day. Bonks adventure was Mario on crack. Dude got as large as the screen on the 2nd game after eating a power up.
Then came sega genesis. It was more of the same graphically but there was different games like sonic and road rash. Larger than life sprites. Golden axe and coop. Snes gave smw, Zelda lttp, ff2(iv), and a few other great rpgs.
The ps1 was the big shocker. Going from 16bit to that, especially when I didn't game at all in high school (I got ps1 after graduating.) it was like gaming was growing up with me. Genesis had games aimed at teens, Nintendo kids and ps1 was for adults. Tekken, ff7, raid rash 3d, tomb raider, resident evil, dual shock, Suikoden, parasite eve, mega man legends, bushido blade, grandia, legend of legia, legend of dragoon, vagrant story, vandel hearts. Diablo, civ, and other pc games on it too. Was the best wow factor.