These sorts of long-term deals for players in their pre-free-agency years have become so common that I often don't even comment on them anymore, but Nick Markakis' six-year, $66 million deal is so huge that it's tough to ignore.
Markakis would have been eligible for arbitration for the first time this year. His contract isn't dissimilar to the seven year, $70 million contract (with an extra team option) to which the Jays signed Alex Rios in 2008 when Rios was also eligible for arbitration for the first time, except that Markakis is a better player. Markakis probably would've made about $20 million, or maybe a bit more, in his three years of arbitration, so this deal effectively buys out three years of free agency for about $45 million. That's a lot, but I see no reason Markakis can't continue to perform at a high level--he's athletic and healthy, and he only recently turned 25. This deal takes him through his age-30 season.