I have been traveling and working via my laptop for the last two years and come across some amazing places. My personal favorite place on earth is a small island in Brazil called Ilha Grande. It's very small, laid back, affordable, beautiful nature (hiking, beaches, crystal clear water). It would not be a very good retirement location IMO. There is one car (belongs to the police) and not a single bank or ATM. If you want to relax and forget about stress, I would recommend
this little hotel (reserve the upstairs room with an ocean view and hammock on your balcony) for a week. It costs about $60/day including a nice breakfast.
As for a livable city that is very nice, I really like Florianopolis, Brazil (where I am now). It's an island about 200 Sq Miles and has some great neighborhoods (Jurere International). I compare it to Hawaii but instead of Polynesian influences you have samba and bossa nova. For those of us with US$ Dollars our advantage is currently not very good because of the week dollar (and strong Brazilian Real).
One of my personal favorites places in the USA is in the Colorado Rockies. There is are a couple of gaming towns in Gilpin County (Black Hawk and Central City) about 40 minutes west of Golden. There is a tiny road from I-70 to Central City called "Oh My God Road" and it winds up the steep mountain side revealing an amazing view of the Continental Divide. With gaming in the county property taxes are nearly non-existent and amenities of the casinos (restaurants, entertainment, etc) are only going to get better with time. So my pick would be a nice place on the top of a mountain in Gilpin County, Colorado with a view of the Continental Divide.
If any of you go to the Seychelles, PM me, I know a guy who has a big catamaran for charter there and he might hook you up with a discount if it's not chartered. I did some research about going to the Seychelles for a few months and working from there and was surprised to find 1.5Mbps internet connection easily available.