From more recent ones Wrestlemania 29 and not getting triple threat with Punk vs Rock vs Cena. Cena hadnt beaten Punk lots of times before he had beaten him on RAW before Mania to cement his place and hadnt beaten The Rock in "Once in a Lifetime" match. At Wrestlemania he could get double redemption and get both of them instead of just rematch with Rock. I mean, Cena is always about overcoming to odds so could be great story in how he managed to get both of his "nemesis" from previous year in one night.
Also from same year prior before Mania perhaps Bryan vs Rock. At RAW 1000 Rock gave Bryan wedding present with "Rock Bottom". Before that Bryan promised that someway somehow he would manage to get title till Rumble and get to that match with Rock. Would be at least good promo in that with video package from RAW 1000 and how he managed. Ofcourse that would meant heel Bryan at times when he was with Kane and started to get heavy over as "Hell No" but could work out. Always found his work as heel as underated.
I totally agree with these. Bryan/Rock was an awesome tease & it always felt like it should've gone somewhere. & as much as I enjoyed Undertaker vs. Punk at WM 29, the triple threat was even mentioned by Punk himself on Cabana's podcast as what he thought was the better booking option & I think most fans agree. Also I agree that as much as I would've loved to see Bryan vs. Lesnar at some point, due to injuries & timing it just doesn't seem like it was ever really possible.
But here are a few other more recent booking decisions that were really disappointing...
Wrestlemania 27 - WWE Championship: CM Punk vs. John Cena & Ladder Match for the World Heavyweight Championship: Edge vs. Christian - I love the Orton/Punk match & the Edge/Del Rio match was surprisingly good at the time & has only gotten better due to it being Edge's last match but WM 27 had a lot of issues overall & the weak World Title matches stick out to me like a sore thumb. I remember many fans wanting to see Edge vs. Chrisitian for the World Title, specifically in a Ladder Match which would've been epic & a huge call back to their attitude era days. & considering Christian went on to have his biggest run right after that & it seemed a little early for Del Rio to win the Rumble match, switching out Del Rio for Christian & having Del Rio get back involved in the WHC title picture after Edge retired seems like the ideal situation looking back. & As for Punk/Cena, the story was already in place just months prior & a lot of fans still believe Miz didn't even deserve to win the MitB briefcase, let alone main event Mania as the champion. Many even consider it one fo the worst mania main events of all time. & to put the cherry on top, Rock running in & attacking Punk & Cena instead of Miz & Cena would've been the perfect set-up for Punk to cost Cena his match with The Rock at WM 28 & ultimately lead to a Triple Threat between the three for the WWE Title as mentioned above at WM 29! That would've been a truly creative 3 year plan for Rocky.
Wrestlemania 28 - I.C. Championship: Cody Rhodes vs. Goldust with Special Guest Referee: Dusty Rhodes - This is kind of a minor one but Big Show had no business being in the IC Title picture, let alone winning the championship. Cody was basically at his peak, Goldie was just starting to return again & a simple switch of just one of the competitors would've given the fans what many still want to this day. It also would've most likely been a much better match & it also would've made for a much more memorable Mania moment.
Elimination Chamber 2014 - Chamber Match: The Shield vs. The Wyatt Family & Rematch at Wrestlemania XXX - These were two HUGELY missed opportunities IMO, surprisingly more so at EC because literally all that would've required was lowering the chamber & letting the match take place inside the structure. Sure they would've had to change the ending of the match but then that could've led to a rematch between the two teams at WM 30! Instead of the super-quick & pretty much pointless squash match with the Shield & Harper & Rowan not getting to wrestle, The Shield could've had an epic rematch beating The Wyatt's, cementing their place as top babyfaces, having a huge Mania moment (that is kind of lacking from their history) & it would've set up much better for their final epic confrontations with Evolution. Instead we got three straight 6-Man tags between the two teams, two of them occurring on TV for free & one of those was on Main Event.
Night of Champions 2015 - Sting wins the WWE Title & Sheamus Cashes In - This may seem like a weird one since it just occurred recently but considering it was probably Sting's only chance to ever win the WWE Title, he looks to be pretty banged up now & his in-ring status is in question (not to mention the WWE Title pictures looks to be extremely stale heading into HiaC), I really think this scenario should've taken place at NoC this year. Rollins' title reign has been highly criticized & I think it'd do him some good to actually lose the belt & kind of hit restart after winning it back for a 2nd reign. It would've been a much better ending to the PPV too IMO rather than just having Kane return. Also that way Sheamus could've spiced up the title picture for a month or two, lost it back to Rollins or whomever rather quickly & be done with it. Now it seems like Sheamus will hold onto the briefcase for a while & possibly even have a lengthy reign down the line.
There's also a few other scenarios that I would've liked to have seen take place by now like a Shield Triple Threat for the WWE Title that almost happened at Payback this year, Ambrose winning the World Title, etc., but they're still all very plausible for the future & the situations may have not been absolutely perfect at the time.