Young up and comers are too risky to end the streak with. Like what if they had this idea a lot sooner, like with someone that was young and really hot back in the day, someone like Brock Lesnar. And Brock was pushed almost as far as a guy can get, I can only imagine how many titles he would've won if he never left. But despite the huge push and being very close to the top of the mountain he still left, and the streak wouldn't have been nearly as impressive as it is today.
Here's one possible way I would've like to see Taker go out: At WM30.
I absolutely love taker but it's clear that he really can't go much longer, much less at a high level. Chances are 30 could very well be his last great match. So picture this: Authority has pretty much squashed anyone that tried to oppose them. Bryan, Show, Cena, Punk, you get the point. HHH cuts a promo saying that there's no one left to oppose him, now he can finally run things the way he really wants to, blah blah evil stuff.
Taker comes out, and that eventually leads a Authority vs Taker's career match at WM.
Taker wins, HHH/Steph "gets fired", loses, retires. HHH can also cut a promo on how he's still pissed that Taker ended the career of his best friend, and now he finally gets a chance to do the same, just to add more into this idea.
Naturally it's a no DQ match, and shield eventually gets involved. They beat him down, setup him up for the triple powerbomb. Kane runs down, and says that he wants to do it. HHH is all smiles and motions Reigns to move aside. Kane gets into position, and then grabs Reigns by the throat and gives him a chokeslam. Meanwhile Taker recovers and the Brothers of destruction fights off Rollins and Ambrose. HHH runs off to get his signature sledgehammer, but then runs right into a double chokeslam. Then Taker does his final tombstone piledriver for the win.
The main motivation behind this idea is there is one thing that Taker was really famous for, and that was being the one hero that would take out the villain that no one else could. What better way to end his amazing career then by taking out the biggest villain we had in years?