Basically, there is actually no "better" file system- it all depends on your usage, and what scheduler you choose. You can look at all the ongoing benchmark comparisons of the Linux file systems and scheduler choices at Phoronix.
They go back for years- this is one of the latest. Seems like every week or so he comes out with a new test run on the new kernels.
Basically, if you choose ext4, you might consider using the data=writeback tweak instead of the data=ordered default, for a boost in desktop performance. That's not without its drawbacks though, as there is a slightly higher risk of data loss/coruption in case of a power loss. However, I've used data=writeback on all my tweaked ext3 and ext4 desktop systems for years, and never had any problems.
In the past, XFS was usually considered the best choice for usage patterns dealing with extremely large files, like huge video and audio stuff. However, it didn't perform quite as well as tweaked ext3 or ext4 on other usage scenarios.
Like I said, for best overall performance you select the FS and scheduler to suit you usage pattern, and that takes a bit of detailed knowledge. There can't really be one FS that will always be "the best" in every circumstance. Plus, remember all these things are in constant development, and change quite often, and even regress as well as improve. So you need to keep current, and Phoronix is certainly a great place to start. Keep in mind that if your Linux install has several partitions, like boot, root, home, data, a separate /var partition, another data partition for a huge multimedia lib with huge files, etc., it might be preferable to use different file systems on different partitions. Again, this takes some thought, and being sure the proper kernel options are enabled. It can get very complex.
All that said (and seemingly now contradicting myself), years ago with low performing hardware I used to setup all my Gentoo desktop systems with multiple partitions and file systems to extract every bit of performance I could, but for the last few years I've gotten away from all that. Today's hardware is so good that I've changed to just installing all my distros on ONE partition, not even creating a separate /home. It doesn't seem to make any difference these days performance wise for a desktop, except maybe for a partition for mega multimedia files using XFS. Re-installs are so easy, and if you keep your data backed up regularly, even having just a /home partition seems pretty pointless, especially if you wish to multi-boot several distros on the same hard disk.
Anyway, that's my 2 cents.