Short answer, neither.

Long answer, I guess it depends exactly on what you're doing....

Personally, I'd have a look at luminary micros range of cortex M3 processors, they don't have anything in DIP, but they do have some 28 pin SOIC members in the family - and they're cheap. (luminary incidentally got purchased by TI a while back)

They're quick (well, they're 32 bit ARMs, so you'd expect that!), there's no more complexity in designing one of these into a circuit than there is a PIC. They use JTAG (or SWD) so your ICD/ICP can be as simple as a soldering a few components and then hanging it off a parallel port, using an FTDI chip or just purchasing a ready built one for next to nothing. You can use all the GNU tools you're already familier with along with openocd.

Their StellarisWare library is just awesome, they've wrapped up all the chip internals into a logical set of API's (on the bigger parts this library is embedded into the ROM) and they also have an amazing USB device and host stack, you get all this for free.

The support is also excellent, they have a forum with lots of their engineers on, if you have a problem they'll get back to you very quickly.

We have just switched from Atmels SAM range of processors to the luminary range because their roadmap is just brilliant, Atmel have stagnated.

Edit:

You could always use something like this to convert the SOIC to a dip.

http://www.sparkfun.com/commerce/product_info.php?products_id=496