We are winding up a remodel of our so. FL home, which included new windows, doors, and garage doors. The rear of the house has a NanaWall
http://www.nanawall.com/ref=Adwords&_kk=nanawall systems&_kt=85077222-4f3d-49f8-84ed-eb14e3a52628
which is a folding wall of single-light doors which gives us a ~17 ft. clear open space. Apart from the garage doors and the Nanawall, the other windows ran about $800 apiece, installed. South Florida has one of the toughest building codes in the country, which is a direct result of Hurricane Andrew in Aug. 1992. All these openings must be filled w/wind load-resistant devices capable of withstanding the + and - pressures from a hurricane which may take hours to pass. There is also a penetration requirement, they use a gas-powered cannon firing a 2 x 4 at the window from a couple feet away, and the window must not allow breaching of the opening, this is referred to as 'impact windows.' If you don't have them, you need to install hurricane shutters on new or retro-fit construction. As a plans examiner, life safety inspector, and ff/paramedic, I was involved in everything from vetting drawings and plans to site inspections for construction practices.
Buy the best quality windows you can afford. The inert-gas windows will probably leak over time, the triple-glazed windows are for -30* C areas. Vinyl is probably cheapest. Vinyl covered wood frames like Andersen are very good, and should last a long time. Marvin is another good brand. Pella is too. In FL two brands which pass the impact tests are PGT and CGI. We bought CGI after I examined the shop drawings for the method of construction.
In the frozen north and where it's below freezing for weeks at a time, the method of installation is probably as important as the window itself. I suggest you go to your local building dept. and ask the structural plans examiner what he or she considers the best, the best for the buck, and what to stay-away from. You might have a tough time getting an answer on that last one.
Be prepared to pay, it's worth it to have the better product if you're gonna be there for years. Pay attention to the thermal break design, these should conduct far-less cold to the inside, not 'sweat,' and are probably more-expensive.
My two garage doors, impact resistant and the highest rated insulation I could get, cost more than my VMax I bought from the dealer in Ft. Lauderdale in 1993.