It was tough to watch this show at the start of season 6. Laurie had married Fez at the end of season 5 and all hell had broken loose. Red had a heart attack. THis was going to be an integral part of the sixth season. But lo, and behold. THey had to change it because the part of Laurie will now be played by Christina Moore instead of Lisa Robin Kelly. I was ready to give up on the show. But the writers muddled through somehow, by minimalizing Laurie's involvement and focusing more on the Red-Fez dynamic and Fez's desire to become an american citizen. Once they did that, I was satiated. Crisis averted.
Another aspect I enjoyed was the sense of impending doom with the gang. Kelso went off to police academy after he knocked up a hot librarian (and in typical Kelso fashion botched both with disasterous results), Eric and Donna set a date to get married, all the while expressing their doubts and fears about whether it was the right thing to do, and Hyde and Jackie got back together, but kept sparring over the direction of their relationship. Most of these storylines would have longlasting effects on the characters and the directions their lives would ultimately take. This season is the one where they became adults, more or less.
And of course, who could forget Pam, Jackie's mom, hooking up with Bob? This was one of the better twists of the season, as it really forced Donna and Jackie to kind of set aside their feelings towards the others parent and work together to pry them apart without getting anyone hurt.
Overall, it was a good season. Not the best. But still solid. THe best season, IMHO, would be season 3, due mostly to Dine and Dash, and the breakup of eric and donna. But still, what a show. I sorely miss it, and wish Topher Grace had not gotten that part in SPider Man 3. We can manage without Kelso, but no Eric was a show killer.