I don't know about other Macromedia Fans, but even after all these years I still have a difficult time using any other bitmap and vector graphics editing software other than Fireworks. I held onto my copy of Macromedia Studio MX 2004 for years hoping to never have to update to the Adobe Software. Still annoyed after all these years that Macromedia sold out to Adobe, I finally broke down and purchased Adobe Fireworks CS5.
Although I also own Adobe Photoshop, if you are doing graphics for mainly the web and not a high-end web designer or graphics designer, I personally would look at Adobe Fireworks before trying Adobe Photoshop. This has nothing to do with money, but workflow and productivity. I find the Fireworks UI much more intuitive and easy to navigate for most web graphics design needs.
As much as I tried to use the very popular and free, Paint.net, which I would recommend for people for general graphics editing, I have a difficult time navigating its interface and being productive. If you haven't spent years using Fireworks this may not be a problem for you.
An article on SmashingMagazine.com has some really interesting comments regarding Adobe Photoshop vs. Fireworks. Although I believe the two products serve two different types of needs, the comments have some really good insight that I overall agree with in terms of the usability of Fireworks for general web graphics needs. Check it out here.
A pretty nice description of Adobe Fireworks CS5 on Amazon, too.
David Hayden