Joe Raedle Cisco’s (CSCO) planned $28 billion acquisition of Splunk (SPLK) and Exxon Mobil’s (NYSE:XOM) $59.5 billion deal for Pioneer Natural Resources (PXD) are among the best bets for deals to close this year. “We think that the Splunk/Cisco deal is one of the most high quality deals out there,” Roy Behren, co-president and co-chief investment officer at Westchester Capital, said in an…