To the headphone guys, looking for some help (first time buyer)

[tbizzle]

Hi guys, I'm new to the headphone game so I have a few questions. I can't watch movies or listen to music late and have been looking at some Sennheisers for a while now. Based on price and practicality, I've had my eye on either the HD595's or the HD555's, but am looking for some advice on which will suit me best.

Now, I'm not an audiophile, but I do listen to a lot of music and watch a lot of movies and I just want them to sound great. Since I'm not a dedicated audiophile, I don't have a headphones amp. I usually just listen to music on my PS3. Also, the majority of my headphone use will be for listening to music and watching blu-rays late, playing computer games and watching Netflix movies on my computer, or listening to my iPod.

So my first question is: knowing what my primary headphone use will be, are the 595's worth the extra cash? I have no problem paying the extra money if I will be more happy with them.

Second, does my receiver, an Onkyo 805, act as an effective amp to drive these headphones? I know it's not a dedicated headphone amp, but does it act as an amp and give them more power than say, plugging them into an iPod? This is probably my main concern because I'd love to be able to watch movies/listen to music using some nice headphones plugged into my 805.

Well I appreciate any help, thanks in advance