I'm talking from personal experience, read comments and verbal comments... most I've have heard from/spoken to think the Xbox 360 controller is better, more comfortable to use - especially for extended periods - it's just generally better designed IMO, unlike the PS3 with it's "afterthought" thumbsticks. They're at completely the wrong angle for natural use, with the d-pad being in prime location when the analogue stick is normally used. The pad should have been properly re-deigned when they chose to add analogue sticks.
I completely disagree with driving games being better on the PS3 controller, unless you like to use the D-PAD

Not to mention the front, but the accelerate/brake triggers are much better on the 360 controller too.
I haven't played any fighting / hack and slash games in quite a while, but I can see how button bashing games are a bit easier on the PS3 thanks to the button response.
Many PS3 exclusives? The Xbox 360 has roughly twice as many exclusive titles than the PS3, according to the quick google search I just did. The exclusives, are however, the only reason I bought a PS3. If using exclusives as a guideline to choose a console, the X360 is the logical choice unless there are some exclusives on the PS3 that stand out more to a person's preferences.
I, and many others, can't use the PS3 controller for extended periods without suffering from aching hands - whereas I've never come across a similar comment about the X360 controller. The original Xbox controllers were a bit big to begin with for some, but they fixed that quite quickly I believe.
There are reasons for and against both, it's up to personal preference... I have both and for me, the Xbox 360 is the clear winner.
In my group of friends, I'm the only one to own a PS3. They don't own one for the same reasons mine doesn't get turned on much & when it does, it's either hooked up to a CSR Elite for GT5 or the odd move game - i've still barely touched games that require the use of the controller - shame.
I should start looking out for aftermarket controllers - I remember getting a couple of my PS One years ago that felt so much nicer to use than the official controller - they were quite similar to original Xbox controllers.
EDIT: Plus - 4 hours to download 2.5GB worth of patches on a 100MBit connection - the PS3 update servers are useless.
Then there's the install to HDD functionality on Xbox 360 + a much better online (you get what you pay for & £3/month isn't exactly extortionate for a relatively well maintained service!).
Forgot to add... there are things I prefer on the PS3 over the X360 too... this isn't completely one-sided - I just think the pros of the 360 exceed the pros of the PS3.
For example, the PS3 has been leagues ahead of 360 in terms of general menu interface since its release and the current iteration is simply gorgeous! Ignoring the controller, it fells like a more "grown-up" console. Everything being integrated since day one, ok - I have the latest versions of both consoles - but I remember the annoyance of a £60-80 wifi adapter. My first PS3 gave me blu-ray when stand-alone players were in the realms of the cost of the PS3. Sure there's more... you get the idea.