Depending on the game, yes I am. I wouldnt buy BOTW or MK8 for the Switch if I already have them for WiiU even if there is differences between the versions. But I would buy Suikoden II 8 times for 8 different consoles if that was a possibility even if its the exact same game each time.

My double dips create a very short list.

Bioshock - Bought 1 and 2 on both PS3 and 360, bought infinite on PS3, bought the collection on PS4 and PC.
Mass Effect - Bought the trilogy as it came out on 360, bought the trilogy as a package on PS3
Final Fantasy VI - I have bought every iteration this game has ever been released in here in NA.
Chrono Trigger - Bought the SNES and DS versions
Final Fantasy VII - Bought the PS1 and PS4 versions
Final Fantasy VIII and Chrono Cross - Bought for PS1 and then again on PS Store later
Final Fantasy X - Bought both PS2 and PS4

That's about it I believe.

Will be editing more in as others mention and trigger the memory for me

I bought GTA V on ps3, PC and PS4.... also have Rocket League on PS4 & PC.

But I usually don't double-dip. I've bought a few remasters this generation but they're all games I've never played before...

Generally, no. I will be buying FF12HD though.

Went off the idea after FFXHD, as about 3 month later I got a PS4 and then 3 months after they announced it for PS4. Can't bring myself to buy Wipeout Collection, I own Fury on PS3, prob won't play it ever again as there was no 'upgrade' option as it's on my PS3. Love Stardust HD, won't get Stardust for PS4 as there is no upgrade option.

Only on my absolute favorite games, I mean the top of the line. It's pretty rare. I've also set an objective to own one of every retail release of every Zelda game. I only still need the GBA ports of the NES games.

The most I've bought a game, counting accidents or whatever and digital releases, I've bought both Link's Awakening 4 times (2x GBC, 1xGB, 1x3DS) and Ocarina of Time 5 times (2xN64, 1xGC, 2x3DS) even. Others I've bought multiple times are among others a couple of Mario games among them Mario 64 and Yoshi's Island, Knights of the Old Republic and the only PlayStation game I ever bought twice is puzzle-game Kula World, which was for PS1 but later rebought digitally on PS3.

I've done it more this gen than ever before with newer titles, and purchased old school 80's arcade games more than once. Sometimes, I'll buy a physical copy of a game I already own if it's on sale, but that practice has largely stopped due to it being insane-ish.

Well I bought the Nathan Drake collection before Uncharted 4 and the Wipeout omega collection so yes.

Well I bought Ocarina of time again on 3ds and I bought MK8D again

I own all of the Metal Gear Solid games multiple times. Oddly since the BS revolving around MGSV, and how they screwed and continue to screw Kojima, I just have my OG copies of those games, and haven't picked up the new combo packs. Fuck Konami.

Very rarely, only in special cases