When Mark comes down with chickenpox, Tim (who's never had it) has to move in with Al temporarily. Hilarity Ensues, natch, but then Tim explains why he always makes fun of Al - he considers him to be like one of his brothers.
Also featured is a neighbor that Al has a crush on, who he tries to impress by saying he hosts Tool Time and Tim is his assistant. Though annoyed, Tim begrudgingly goes along with it - only to later let it slip by accident that he's the host. When Al's about to come clean over lying, Tim intervenes by calling Tool Time "our show."
Al's mom's funeral, for having a lot of hilarious moments in it, manages to have one of these when Tim goes up to the pedestal for his speech. He said that while Alma was big, she compensated by having a big heart.
Especially when Tim says that Alma was Tool Time's "biggest fan," which comes across as yet another fat joke about Al's mom until he reveals that this was Alma's favorite joke.
Tim gets another moment of Hidden Depths when he helps Jill cope with the loss of her own father.
In that same episode, he also helps Randy, who had turned his snark to high as a defense mechanism, by giving him an outlet to crack jokes to without upsetting the other mourners.
Another Tim and Al moment, when Al is fed up with his role and requests that he gets a shot of hosting with Tim as his assistant. Since it's a Vetinari Job Security episode, Al fails horribly and the show is going so bad that Tim has to abandon making jokes just to help Al get to each new step of their project. Finally, when Al looks like he's about to just give up, Tim slips back into his hosting role by making his usual So Bad, It's Good puns and getting the show back on track. Al is appreciative of Tim saving his disaster while in turn gaining an appreciation for Tim's role.
In on episode, Tim finds his first car (a 1966 Chevy Corvair) in a junkyard, but it's crushed before he can buy it. Jill then goes through a bunch of old car magazines to find him a new one. She does and trades in her car for it just to make him happy.
With a lot of Mood Whiplash, though, as Tim reveals that the guy who did so ripped her off (her Austin Healy was worth more than twice as much) and that it wasn't that he wanted a Corvair. He wanted his Corvair. He insists they trade it back, but takes her for a makeout session in the Corvair first.
Randy and Lauren's first official date. After a series of disasters and Randy feeling insecure and nervous as hell, a little advice from Wilson helps him stand up to a cranky waiter, score him and Lauren some free appetizers and gives them the nerve to take the last step in their Relationship Upgrade.
Anytime the boys show that they really care about each other, considering how often they fight.
In a third season episode, Randy insults Tim, causing a rift between father and son. Wilson helps Tim realize that it's nothing against Tim himself, but Randy becoming a teenager as the reason for the snarky remarks...something Tim doesn't understand because he was barely prepubescent when his own dad died (making the moment double as a Tear Jerker). Tim then has a discussion about it with Randy, who apologizes and then tells his father he was sorry his dad wasn't around long enough to see him turn into a jerk. They then hug.
The final episode had Al marrying Trudy in the Taylors' back yard, before Tim realises that the Taylor's back yard is simply too small for the wedding; at which point Wilson points out that if they removed the fence & used his yard too, then there'd be enough room. They then question why they hadn't removed the fence sooner.
Also from the Finale and doubling as a Tear Jerker, in the final curtain call Zachery Ty Bryan broke down crying about the show going off the air.
Zachery Ty Bryan: "I've been coming to this set for most of my life. And now... I... don't know what to do."
When giving a toast after the ceremony, Al goes on about how much his friendship to Tim really matters to him.
In one episode Al invests his entire life savings into a Tool Time board game that is manufactured with bad wiring. Since Al can't afford to have the games repaired or completely redone, it appears that he's going to lose everything. Enter the Taylors, Wilson, Heidi, Ilene and Al's brother Cal who stay up all night at Al's apartment fixing each and every one of the game boards.
When Bud Harper takes over as the Binford boss, he has big plans to expand Tool Time to a national run, but he wants Tim to fire Al (on the grounds that Al's popularity skews toward older viewers who have already bought their tools). Tim is conflicted between his dream and his loyalty to Al, but ultimately he sides with Al and convinces Bud to let him stay on the show.
"Jill and Her Sisters" sees the titular characters trying to plan a party to commemorate their folks' 50th anniversary. Squabbles ensue and Jill eventually goes on a rant about how she can't take it anymore. After she storms out, the sisters openly wonder what her problem was. Tim (who was watching the whole thing) defends Jill, chides the sisters for their behavior, and takes back the complimentary breakfast he offered them.