Having finally gotten my Generations Springer and had a tool around with him last night I can put my two cubes in on this poll:
G1 Springer (1986) - both the shiz and the nit! Awesomely fun toy, loved both his modes, best rotating copter blades they had made and for its time was one of the few autobot ground vehicles that had a gun on it that made (sorta) sense so good to set up battle scenes. Head was a little small on the robot but great sword and gun and actually had elbows which was rare for a toy of that era. You could relate him to a character you had just seen in a movie and tv show which added to the play value.
Timelines Deluxe Springer (BotCon 2007) - never played with him so cant offer an opinion
Universe Voyager Springer (2008) - for its time it wasnt a bad retool, came packaged with Ratbat and the colour scheme was well done. Didn't really come off like someone who was a wreckers leader though as his alt mode wasn't armed to the teeth and of course no 3rd mode.
Warbot Defender (FansProject 2010) - besides my Quintessons I don't generally buy 3rd party stuff so again, cant offer an opinion
Generations Deluxe Springer (2012) - didn't end up getting this guy because by the time he was available scuttlebut about the Voyager was out. I do have other figures that share the mold though, and besides being a bit spindly it is quite good with a great attack chopper mode. Again sadly, no 3rd mode.
ROTF & Robot Heroes Springers: Seem to have been left out of this poll, cant really say its a massive loss. Have both, neither very good.
Generations Voyager Springer (2013) - Now this bloke I took out of his box last night and had a play with. Good transformation, pretty inutitive, alt modes are certainly mre different to each other than the G1 mold. Not a fan of his copter mode but LOVE his armored car mode, big strong & sturdy. Reminds me a little of the size deluxes used to come in back in the Armada days. Robot mode a tiny bit lanky but great.
In the end, I still had to give me vote to the G1 toy, just for what it was capable of given the tranformer toy engineering of the time, the play value, and you could relate it to a character you had just seen in a movie and tv show. But Generations Voyager came a damn close second for me, if I had liked the copter mode more it would have come out at the top!