I think it's usually only twice with a few series. I'm not really a fan of double dipping, unless the original game is a strain to play.

The original Sonic the Hedgehog. Got the original cart, a multigame cart (didn't have one of the games on it, forget which one), and a few Sega Genesis compilations.

Pretty much all other games I've purchased twice at most.

Oh Dragon Age for me I bought it on the Xbox360, then my 360 broke and I bought it on PS3 but then I bought a new Videocard and I decided to buy it on the PC because the console- port was horrible, so thats 3 times!

I have bought many games twice, buying PC versions later, like Fallout4 because the loading times where too long on console and old PS3/X360 games cuz they just looked better on PC and where very cheap on sales (under $5) like Mass Effect 2 and Bioshock series

The cheats it has are speed run, turn off random encounters, and automatically heals and gives infinite limit breaks making the game very easy to play through and platinum if you like to trophy hunt ;P

Xenoblade Chronicles. Friggin' love that game. Bought it twice physically for Wii (2nd copy I bought at $50 before prices doubled to over $100 just so I'd have a sealed copy). And then bought it twice for 3DS, lol, once physically and once digitally because it was too tempting to buy it at midnight. And then, of course, I bought it on the Wii U VC on the eShop. So, 5x. Not sure what else would compare. Oh! Ocarina of Time, N64, GC Collector's Edition, Wii VC, 3DS, Wii U VC. 5x.

I am going to buy RE4 for the third time.

Devil May Cry (the original). I must have bought and sold the game over half a dozen times. I completed it, traded it in and then whenever there was a drought or i couldn't find anything that I was interested in, I would by it again.

I'd never waste good junk food money on stuff i already have. Although i have pirated some games enough times so the ad revenue i generated for site X would pay for a copy or two.

Mega Man X / Maverick Hunter X. I'm just going to throw the original and the remake together.

2x SNES
1x PC
1x Gamecube (part of the Mega Man X Collection)
1x physically on PSP
1x digital on PSP/Vita
1x digital on 3DS (just released last week in europe =D)
1x iPhone

8 times in total. Totally worth it, best game ever. =P

I've only done that very few. Resident Evil 1. Only because the original version has material not in the remake. And Pokemon Fire Red Leaf Green. I needed to complete the Hoenn Pokedex. I can't think of anything else. I always avoid rebuying series over and over. Once I have it somewhere. The the exception is digital only games, that get physical copies later on. Like Minecraft and Shovel Knight. The 3DS ambasador games. But those don't really count here. Oh, and the GTA Steam bundle. I got the steam versions. Because I thought I was gonna get away from GFWL BS. I didn't check that it was still in the steam version. I was using common sense. "Why would copy protection and a secondary service be with steams version?"