The only investment of a VC style I've seen in the last few decades that surpasses Softbank's return on Alibaba, is Naspers with Tencent. Until their recent $10b sale of some shares, they owned 1/3 of Tencent.
"The stake Naspers bought for just $32 million in 2001 -- when Tencent was an obscure Web firm in a nation where few people used the Internet -- is now worth $175 billion."
"While the investment has made Naspers the most valuable company in Africa, its market capitalization of about $122 billion lags well behind the value of the Tencent holding, suggesting investors assign no value to its other businesses."
https://www.bloomberg.com/news/articles/2018-03-22/naspers-s...
There have been a few massive percentage returns that have been similarly outsized over the years, not equal to the top line scale however. Peter Thiel's investment into Facebook produced something like a 5,000 fold return.
The parents of Jeff Bezos put $50,000 into Amazon in its initial $1m round, which has produced something around a $2b to $3b fortune for them (a ~40,000+ fold return).
There have also been some infamous misses that would have produced comparably extreme returns. Paul Allen owned 25% of AOL right before it become a giant; he sold his position for a few hundred million dollars in a fit, because they wouldn't allow him to buy a larger position in it; that stake would have solidly been worth $40 billion at the peak. [1]
Larry Ellison wanted to buy a very large position in Apple, in the process of returning Jobs to the CEO role. Jobs talked him out of it on a moral high ground basis. [2] It's hard to speculate what that might be worth today or if Ellison would have screwed everything up instead, could have been a couple hundred billion dollar miss.
[1] https://www.forbes.com/forbes/1999/1115/6412186a.html
[2] https://www.cultofmac.com/428587/larry-ellison-steve-jobs-sh...