I have had tons of iphones
and I am currently using a iphone 5
bought the green and blue otterbox defender the day i picked up the phone..
the otterbox I had on my 3gs was great the one on my 4s was not so hot
(otterbox did send me a replacement)
the one for the iphone 5 seems a bit more rugged that its 4s predecessor just not by much
these cases can be found on ebay at a much better deal than retail
In my honest opinion I think they are woth around 20-25 usd not full retail.
Beardman-
I took a short tryout on the galaxy s3
it was not for me however I bouth a otter defender case for it and it was decent
also bought a 64gb card and ended up selling it all on ebay due to the phone was nice...
I really liked the larger screen but it was not very user friendly
it was not the droid operating system my droid friends could help me with...
and i did not like the strange button sitting at the bottom of the screen.
I decided on trying the galaxy note but went back to iphone due to offering tattoo work for A iphone 5.
the Galaxy note is essentially the same chips and such as the s3 just with a even larger screen and in my opinion a more durable
casing.
I have a friend who is a total cell phone nerd and he tries to keep me up to speed on this stuff...
The iphone 5 case has a few differences from the iphone4s case
notably the camera lens opening:

and the most noticeable difference in the front is the fact that the home button cover is redesigned to
resist becoming misshaped.
like i said above these cases are all avail on ebay at about 40% off retail and that is your best bet.
I would also like to add this...
I am quite disappointing in apple products and the fact that they never really offer anything new
a new device comes out with a barley noticeable tweak and customers buy it up for exorbitant pricing.
dont try to sell me on oh the screen is a half inch longer or its 1.3 seconds faster...
I as a consumer want real upgrades from previous models.
do i like having a nice capable device in my pocket? you bet...
are we really going to keep buying the same device over and over every year?
I for one will not.
Sorry for the rant....