There's not a huge difference between the two. I do like some of the newer features in CS5, but it's really just preference. It depends on what you're doing too. If you're doing a lot of retouch work, i'd say cs5, but really, designing and other things is pretty much the same.
Well, CS5 is definitely better, the latest and greatest - and I can see no reason to try to buy CS4 instead (if you could even still find a safe copy of it)
I choose CS5 because this is updated , although your question is which one is easy, answer of your question is cs4 this is old and usage is easy and cs5 is updated some new features are added with it. So for you cs4 is best. I like cs5 because of its extra feature.
I like CS5, but for some reason adobe keeps making their software more and more difficult to get used to. My personal favorite was CS2, but it lacks some of the cool features CS5 has. Meh.
You'll find that most creative professionals update to every-other Creative Suite release. For whatever reason, the industry all had CS3, and now CS5, but most skipped CS4. This means that if you're handing files between you and another designer, they can open your documents if they have CS5, but you wouldn't be able to open their unless they specifically exported in a legacy format. Photoshop should work just fine, but Illustrator and inDesign aren't going to be that easy. I would say go with CS5, the only people I've run into who have CS4 are those who just got into the industry and that their first Creative Suite purchase.
CS5 is best from CS4 because this is new version and new features and options are add in it so i suggest u CS5.
i have just started use cs5 cs4 very easy both are same but cs5 have some nice features and also some different shot cut key like we use shit+k for Slice tool but here we are using C slice tool any how looking good lets see what i have found some thing cool in cs4 then will share with you
CS5 is packed with many features, however people out there still use Photoshop 7 and are just fine with it.