I have used the PIC18F2550 / 2455 and the PIC18F4550 and it they are reasonably easy to use.

If you are obviously using PIC Basic then i strongly recommend you download EasyHID which will generate a base code in PIC Basic and VB for use with this PICs. With this base platform in both languages generated for you, it will assist as a excellent starting block for your project.

It generates the HID and PID codes also for you for specific USB device recognition.

EasyHID can be downloaded free at http://www.mecanique.co.uk/products/usb/easyhid.html

Sending data too and from the PIC is reasonably easy.

The other option is to use standard RS-232 but then use one of FTDI range of chips to give you that simple USB interface with no additional components.

Hope this helps,

Steve