Jim Cramer, in kicking around the latest Microsoft ( MSFT) rumors in a TheStreet.com Web video Thursday, said the software giant "would ruin" Research In Motion ( RIMM) if it were to acquire it. "Unlikely they'll be bought," Cramer said of Blackberry device maker RIM, a $45 billion market-cap company. Cramer told stockpickr.com's James Altucher that RIM was "incredibly overvalued on a takeover basis," although he believes it's a "supreme company." Cramer said Microsoft is "so IBM ( IBM) in 1988, it's frightening ... they think they're a nimble growth company." What about Microsoft buying Yahoo! ( YHOO)? Altucher asked. "Yahoo! does have 10 bucks cash a share and securities, and Chinese e-commerce company Alibaba," Cramer said. "I think Yahoo! has the worst management of the Net," Cramer said. "Microsoft could vastly improve Yahoo! if they had it. "Microsoft should bid 28 for Yahoo!, and get Yahoo!, but they won't because they think MSN (Microsoft's commercial Web site) is better than Yahoo!," Cramer said. What Cramer found most intriguing was the prospect of eBay ( EBAY) buying Yahoo!. Cramer said that in an eBay-Yahoo! merger "you'd see both of them fly up. Marriage made in heaven. I would love it. eBay actually could do something with Skype (its Internet telephone service). The combo would own auctions worldwide. "Microsoft, other than aQuantive ( AQNT), feels it's better at everything than anyone," Cramer said. "Maybe it was at one time. But that's a terrible amount of hubris to run a company with."