I use coral paint shop pro I find it a lot more user friendly, less resource intensive and frustrating than photoshop. Plus you can also open edit and save as photoshop files as well. There are a couple of annoying things since the move to Coral rather than jasc like some really useful tools are off the toolbar so you have to manually put them in and the instructions are a bit crap for some things, but apart from that it is very good. For resizing/cropping large amounts of photos and adding some nice effects I use media resizer pro as it is fast and simple. For easy 3D mirrored and tilted imagery I use box shot 3D.
I have no doubt to say that Photoshop is the best software to create any design you need to make. A lot of free useful tips available around the internet, you just need to search and download it.
I have PS CS4, but I tend use it for only photo editing now... For web, I swear by Fireworks! its just so much faster than PS!
When photomanipulating, vectoring, and designing PSD layouts for webs, I use Adobe Photoshop. and Adobe Illustrator when making digital sketches.