That is a very loaded question and can only produce controversial answers i.e.; "The '76 Bronco Ranger package was arguably the best Bronco ever produced."
With that said, the Bronco changed in function mostly over the years and it seemed that when something good left something bad came and vice versa. When power discs came away went the crossover steering. '77 was a nice finishing year with all the goodies and a few trim packages but it had the fuel doors and are the quarter panels are harder to replace. With all the niceties of the '76 + '77 the US came up with the emmissions. That makes it more difficult to register them as a daily driver. All in all the '71 to '74 were the strongest years and out of the emmissions curve for most states plus had the stronger front/rear ends, automatics (stronger than manuals), and power steering were plentiful. With simple junkyard additions (disk brakes)and a booster they can be driven comfortably. Of course you get a '76 or '77 with all the goodies and register it with a bought title from an earlier vehicle.