And Liquinn is totally right. Buy what you need when you need it. There isn't a model of mac out there right now that I would call obsolete, other than the towers (which are still great machines, just that you can build a hackintosh that's twice as powerful for half the price because Apple isn't keeping up the pro line well enough [even more true when you consider that that statement was pretty much true on the release date of the current tower model as well]). Speaking as a designer, the pro line seems like it's currently only concerned with volume costumers and the support they need, not staying current. For anything other than a server farm or a desperate need for PCI cards, I'd go with an iMac over a tower right now.
/unrelated rant
Haha Loved your rant btw. To be honest though, I wouldn't be able to use an iMac with what I need my Mini for, which is why I'm buying the Mini and not any other Mac.
Let me explain that. I'll be getting the 2.7ghz i7 Mini, upgrading to 16GB RAM, and putting my OCZ Vertex 4 into it after wiping clean. I already have a wireless keyboard from my wife (bought it for her iPad. It's still in the box a year later...), and magic mouse and magic trackpad from my sister (just bought a brand new MBP last week. Thought she might need it if she hooked it up to her TV. She didn't realize it would still work...)
I'll be using my 60" Sharp LED for my monitor. So considering I already have a monitor, keyboard, mouse, and trackpad, getting a computer with any of those would be redundant and useless to me. Me and my wife just quit smoking (terms for me getting a new computer ) and we'll be saving about $3000 a year because of it. We decided to split the difference and both get something for $1500 or less.
The Mini itself will be $966 right from Apple (with shipping and taxes) and the Upgrades are $260 from Amazon (with shipping, and yes I'm including the original cost of my SSD because I only bought it last month lol)
So the whole cost (with a budget of $1500 don't forget ) will be $1226. That is significantly cheaper than any other Mac I could have bought, with better specs. (2.7ghz i7, 16GB RAM, OCZ Vertex 4 SSD)
That's the reason I chose the Mini as opposed to the iMac or any other Mac for that matter.
BTW, I'm very sorry OP for threadjacking (not my intention) just replying to a comment here to show that some people prefer other pieces of equipment. In the same respect, not attacking the person I'm replying to. Just saying.