I loved this show back when it was on TV, and spent the past few weeks watching the entire series on Netflix. Seasons one and two held up well, I thought, and three to five have their moments, but as others have mentioned it pretty much goes off a cliff after that.
I never noticed how quickly they ran out of steam until binge-watching it. The early episodes usually revolve around pretty simple, relatable situations - the first date, prom night, taking the car out of town to go to a concert, getting caught smoking, parents finding out about them having sex, some straightforward father/son bonding episodes like "Hunting" and "That Wrestling Show," etc. - but by the third and fourth seasons you already start to see some ridiculous, contrived concepts for episodes that miss more often than they hit, some irritatingly forced story archs (namely Eric and Donna fighting over some inane ******** every episode to build up to the big break-up), and lazy, glaring continuity errors (in the episode "Class Picture" alone, there's a flashback scene where Kelso keeps trying to "accidentally" walk in on Donna getting changed so he can see her naked, even though he presumably already would have when they all went skinny dipping in "Hyde Moves In," and another flashback scene where a young Kelso is fooling around with a young Jackie in Forman's basement, even though it's implied in "That '70s Pilot" that Kelso had only recently started dating Jackie and bringing her to the basement).
I'd say watch it up to season five and consider "Celebration Day" the finale. The only episodes worth watching from seasons six to eight that I can recall off the top of my head are "Happy Jack" and "Can't You Hear Me Knocking?"
