So far the Invisible Shield (full body film) is rock solid for scratch-protection… but I think if I had to do it over again, I’d have bought only the front (they sell front, back, and both together for the iPhone).

Being cut from a flat sheet, there are obvious hurdles to applying the film to a rounded surface. The back piece is cut with tabs, to wrap the corners. It worked about as well as I’d imagine any film could, without heat shrinking (obviously not an option). In the end, the sides and corners don’t look as neat as I’d like… but since I’m going to likely get the Incase, it’s just a slight waste of money.

The front however is a different story. I can’t recommend enough this film. Great protection, works great with the touch screen, covers the entire front, with a small cut piece to protect the home button… worth buying, even if you’re using another case. None of the application problems present with the front piece… as the whole screen area covered is perfectly flat, and the home key is nearly flat. I’d only warn you that if you’re squeamish about putting liquid on your phone, then stick to static-cling films. You’ll get your iPhone wet with their application liquid, and will need to leave it depowered overnight.

IMO, many of the cases offer trade offs.

For example, the belt clip that comes with the case-mate is a bit unwieldy. There is also a very nice case from Griffin (Elan) but the belt clip is not removable.
The case-mate also comes with a nice clear screen protector, the leather cover is thin and looks quite nice (some cases do not include a screen protector).

I have never used a BT headset I thought was worth the cost. Most have poor voice quality and have no where near the advertised max 30′ range.

I cannot use my $100 Bose earbuds with the iPhone due to the recessed audio input but the more expensive Apple iPod earbuds (more rounded, smaller buds) are acceptable, as are the included earbuds.

Brandon brings up a good point, that of aesthetics.

The iPhone is a gorgeous piece of engineering.

I’d prefer not to cover it up at all. I may try one of the film-type protectors for a time, though they do not offer even minimal drop protection.
I have one on my 4G iPod and, so far, there have been no issues.

I am still on the fence about which I like better. I like having rubber around my precious iPhone, but then you can’t see it in all its glory. My “favorite” case as far as ease and looks is definitely the Griffin Elan Snap-In, which is a breeze to get the iPhone out of (when you get a call or just to play) and looks sleek.

The only problem is that it exposes much of your iPhone to dings and scratches. I had mine face-in for a while and the back of my iPhone has quite a few scuffs from normal day to day bumps.

Also like how it comes with a screen protector (although who really knows how well that works), and a cleaning cloth (don’t use it, but a nice thing to include).

Only complaints: a little difficult to remove (but still possible), and it seems to look dirty rather quickly (although I am a little OCD like that).

My few complaints would be the $30 price tag for a case with no attachments, and, because it’s rubber, it doesn’t slide it in and out of my jean’s pockets very easily (I’m not a fan of belt clips).