Currently looking into getting a external HDD.
Going to get a Seagate GoFlex 1.5 TB because
1. They offer a free program that costs about $30 dollars otherwise that lets me read/write on PC or Mac.
2. All external HDD's have issues, i merely chose Seagate over WD because of the program. That and they happen to let me choose HFS+ right out of the box.

So my question is which shall I go with? The HFS+ or NTFS? Whichever I chose I receive the program for the other system.

The main reason I wanted to get this is because most of my music is stored on my PC, I've been using my Macbook Pro as of late to download music because I synced my iPhone to its iTunes. I did do a little trick to let me sync between both, but it creates problems, especially with iTunes bought music. It erases all my apps and puts on whatever apps I had when I synced my older iPhone 4 when getting on my PC (even with Sync Apps disabled). My store bought music no longer works when I sync between both either. I have to erase it, resync it, and hope that I don't have to get any music off the other ever again.
All of my movies are also on my PC because of the larger HDD. Don't want to waste to much space on the Mac.

The dilemma I'm running into now is that most HDTV's and PS3 don't use NTFS or HFS+ you have to either create a separate partition or partition the whole thing into Fat32, which doesn't allow over 4GB files. There goes any hope for watching HD movies through this thing. The weird part is, Xbox 360's do recognize HFS+ just so users could listen to iPods. So i could potentially watch any HD movie through a 360 on a HDTV, an easy enough work around.
Problem, if i decide to take this anywhere, lets say to my parents house, on a trip, over to a friends house, etc. Most people don't have mac's and in rare cases a 360. Leaving me to have to lug around my MBP wherever I go.

I'm asking you because maybe someone has some other side I'm not looking at.