They don't really follow a building story (meaning the next one doesn't build on top of the previous) so you will not miss anything if you decide to watch them "out of order" if there was such a thing.
If you are a purist and you want to absolutely see the evolution of style and tech in the stories and want to build upon legacy to get to where we are now, I would recommend you just watch them in the order they were released.
Now, a note up front, they are NOT all created equal, they are not ALL good, but even the bad ones give you perspective into the character. So you can go by the golden list (the ones voted by fans as being the best) and then work your way down the list. You can watch them by actor, although that will get hard at some point as there are a lot of turnovers in the roll.
This is why I would personally recommend you watch them in the order released. Take the different actors, the different style of effects, the good and the bad as they come to have a better appreciation for it. Warning through, there are A LOT of them, so know that its a journey, so enjoy it, don't go for the quick watch and done, it will frustrate you.