Why all the replies here saying "I can build a pc myself, & cheaper than an imac.. etc etc"? This OP didn't ask about DIY pc techie-builds. he wants to buy a computer. Simple inquiry: the pros & cons of imac vs pc's.
pc Pros: read previous posts.
Here's my limited "Switching from pc to mac FOR DUMMIES" about a couple basics:
You said you do Photoshop work. pc's freeze up often & it becomes chronic with big graphics. That's no big deal if you have a brainiac techie friend on call to fix things for you.
If you don't, just shoot the computer & buy a new one (fairly cheap). It feels GOOD.
W/pc's BACK-UP EVERYTHING, CONSTANTLY. You will lose something eventually, one thing being--> your temper.
imac handles graphics better. IME, that is the single biggest "pro" side to mac. freeze ups are rare, all mine have been website-related, not graphics-related. and don't repeat constantly when I log back onto the same site. Why? I have no idea! I'm a dummy.
Pro: Apple stores have walk-in services. My husband has used it for trouble-shooting things he messed up or didn't understand, never had a mac 'break' yet. Con: no Apple store near us. Pro: Haven't truly needed one yet.
Con: Having learned on pc's, re-orienting to macs is harder than I anticipated. but I was much younger & more motivated when learning pc's. *My husband says* I don't take advantage of all the options available for pc addicts to make the transition easier. He uses every option available & does fine. plus he's more motivated, like an Upgrade addict.
Graphics professionals who must have stability to make their living, use macs. and there are reasons for that.
With "Parallels Desktop for Mac", you can use familiar pc programs on macs too.
You probably have a sharp young college mind, and may not need that, but it's available.
Good luck with your decision.