i use paintshop pro myself have done for years, but tubing can be fiddley with it, making sure the tube (image without background) looks good on other coloured backgrounds, never tried gimp but it looks like i may well do soon lol
heres an image i did of my parrot after he died
i removed the background and added my own then played about with different effects
i plan on making pics with amber in, just need a decent camera first