The recent explosion in price differentiation at the box office is starting to make these columns somewhat more difficult. For example: Clash of the Titans set an Easter weekend record, grossing $61.4 million (not including late-night showings Thursday, topping the previous record holder, Scary Movie 4, which opened to $40 million in 2006. Such comparisons have always been a bit misleading, since of course you have to adjust for inflation -- $40 million in 2006 comes out to around $43 million today. If your aim is to gauge popularity, that's not too helpful either, since the increase in movie ticket prices has outpaced inflation. $40 million adjusted to today's average ticket prices is around $46.5 million. Clash still wins, but it's not as much of a rout.

But many of the theaters showing Clash of the Titans are showing it in 3-D, which makes things more complicated still. Variety says that the average price of a ticket to a 3-D feature is $14.73 -- and that 52% of Clash's weekend gross came from 3-D showings. Doing a bit of rough number-crunching, adjusting Scary Movie 4's numbers to a similar 2010 3-D release gives you a weekend number of... around $69 million. Of course, that doesn't mean that Scary Movie 4 should keep the Easter weekend title -- there are a gazillion assumptions built into that calculation, including that people would actually have paid a premium to see Scary Movie 4 in 3-D. But it just goes to show you how dodgy these types of box office comparisons are getting.

More on the weekend's releases, and the top 10, after the jump.