Picking career making matches is tough just because it's like...what qualifies? There's a couple things to consider. A) Would they have been stars eventually and B) Were they already somewhat of a star? Take the Foley/Hunter mention. Did that help Trips? Probably, but Hunter was already a three time champion and it can stand to reason that Hunter was going to remain a main eventer regardless. His blooming relationship with Stephanie McMahon around that time basically guaranteed that. Regardless, Hunter was already a star going into that match, so it's probably less of a career making match as one that helped him get over that last hump.
When it comes to Hunter/Batista, I don't believe the Wrestlemania match did much for Big Dave. Practically everyone expected Batista to lose it at Backlash. After that happened, everyone expected Hunter to win it back at Vengeance. If there's one match that permanently earned Batista a main event spot, it's the HIAC match at Vengeance. Somehow, a guy had just went in and defeated Hunter in three straight PPV title matches. I don't believe that's happened before or since.
Following the same formula for matches that helped others get over that last hump, you can include the entire Rock/Foley feud in late 1998 and early 1999. Rock still had a little ways to go (Mostly just turn face), but the Foley feud helped him start off his main event days as if he belonged. Same goes for the two Foley/Austin matches after Wrestlemania. Back in the day, Foley was the go to guy to ensure a guy's title reign started off hot. Without it, who knows if the reign would have sizzled out or not.
Obviously, there's the most well known example in Sting vs Flair at Clash of the Champions 1.
To some degree, I feel as if Bret Hart's win over Roddy Piper at Wrestlemania 8 did wonders to help Bret maintain importance in both the fans and office's eyes. With how rare Piper agreed to put someone over, it was a big deal Bret beat him cleanly on live PPV.
Another obvious one is Misawa's early feud against Jumbo that helped Misawa go from junior heavyweight into being AJPW's Ace for the next decade.