I like Brendan Nyhan's first table here, which compares the 50th vote vs. the 60th vote in recent Senates. For Senate watchers, it's easy to see that there's a very big difference between getting a majority and getting cloture.
I'm not as thrilled about the second table, which shows the bills killed by the difference between a majority and cloture -- using ADA key votes to find the bills. It's fine as far as it goes, but there are presumably quite a few other bills that the majority didn't bother wasting their time on because they knew they couldn't get to 60.
We just don't know about the others, but I think there's every chance that two huge recent presidential initiatives, Clinton's health care bill in 1994 and Bush's social security bill in 2005, might well have passed given a Senate in which the majority party gets its way. Of course, both bills collapsed long before they reached the Senate floor, but in both cases it's very possible that marginal Members of Congress (from both Houses) bailed because they knew that the measures were doomed by the filibuster. And, as Brendan says, other bills that did pass were certainly altered to avoid filibusters. Even what's attempted in the first place could be different; for example, Obama might have been far more aggressive with his first Supreme Court pick in a 50 vote Senate.
The other side of this, however, is that the rise of the 60 vote Senate has been accompanied by other new rules and practices that empower the majority party. That can be seen in the health care bill debate now, as the party leadership, not independent committees or floor majorities, has has had the almost complete ability to shape the specific provisions of the legislation. As I discussed a few days ago, overall Congressional party majorities are more capable, not less capable, of shaping outcomes than they were in the middle of the twentieth century, despite the 60 vote threshhold.
(UPDATED to remove a quibble I had, which was my own misreading. Oops.)