Yes i bought a 3ds early while no games were coming for it. Traded it in and then later regretted doing that aswell.

Gameboy pocket. Got it as a present then about 1 month later the GB Colour came out.

Other than that I buy most things these days for cheap so for price point I dont regret anything.

....although I got a PSP 3000 for a decent price when it was all but gone and I sort of regret it...

So you're saying you should of went with the 360 which had a even worse hardware failure than any other console in that gen (maybe of any console gen) because your ps3 broke a year and half in? Hmmm. 

Nah. I love 'em all. Sometimes I regret buying one near launch but they eventually become worthwhile.

I always do my research before I buy an expensive gaming system, so no.

I think my single regret was buying a Dreamcast roughly ONE WEEK before Sega announced they were going to kill it. I felt like crying. And then, the price dropped like $100! Still turned out to be a great console, though.

The biggest regret was when i bought the PS3 at launch, then it had no games.

PS4, 3DS, Vita. I should have waited on them all. There's hardly anything on any of them that's worth the purchase even now.

I kinda regret buying my 3DS, I still have the regular model, during the 3 years I've been with it, I still only have 4 games, my Wii U on the other hand is getting all of my attention and money, I already have 8 games on it =P
Also, I wanted to trade it in towards a New 3DS Xl, but I don't think it's worth it, 2 years later we will have the new HH from Nintendo anyways...

I regretted buying a Wii. But thankfully, Xenoblade happened, so it somehow soften it a bit.

Other than that, I've enjoyed all my console purchases.