We think about several hardware comeback stories in gaming.

PS3 had a disastrous first few years with some bright spots until the PS3 Slim launched in 2009, and the software kept coming.

3DS had a disastrous few months after it launched, leading to a price cut (which was a loss for Nintendo) but saved by Mario Kart and Super Mario 3D Land in Holiday 2011 as well as Pokémon in 2013.

Xbox One was selling well even at the start, but its reception improved around 2016 with Xbox One S and in 2017 with Xbox Game Pass and Xbox One X. In fact, those changes likely helped the console from peaking early. Microsoft had to 180 many Xbox One choices before launch and unless they would've stuck with those plans, Xbox One was going to sell millions and millions in its first year anyway. Still, Xbox One hardware was often sold at a loss. And Game Pass at times has lost money as well.

3DS was undeniably profitable and along with Nintendo's massive war chest was the reason they could even make Switch. PS3 lost billions for Sony, even wiping out the combined profits of PS1 and PS2. Yes, it made billions as well especially after its turnaround. But so much money had been lost. 

Are there any other platforms with such rocky moments and even financial losses that were undeniable successes like 3DS? I can't think of any. 

Ps3

Yeah thing with PS3 is that while it sold a respectable number of consoles, it never made back the billions in cash it lost; by the end it was still a net loss for Sony financially.

PS4 really saved them. PS3 lost billions and Vita lost money as well. 

I remember playing a 3ds at best buy and was this close to buying one. Seeing how the games kept on getting better as they came out I am upset to this day that I did not get one.

Yeah, it most definitely one of the few that ever has. But it’s because Nintendo extremely wisely slashed the price as soon as they realized the launch was a failure. Without such fast action on that, it’s very possible it would have been a huge failure too. PS3 is really the only other notable one to turn it around after launch disaster.

I don't know the financials, but Playstation had a very rocky start... it was a bit of a sleeper hit considering other consoles by electronics manufacturers that had failed spectacularly in the 1990s, it wasn't expected to win... until it did.

First off, it was losing to the more expensive Saturn. Second, early versions of it had a lot of difficulties with the disc tray skipping and ceasing to play the games after as little as 6 months. But despite selling a mere 4 million units in 1994 and 1995, 1996 saw a massive uptick in sales, over 9 million units, the system had really turned things around with popular games like Tomb Raider, Crash Bandicoot, Tekken 2, and Resident Evil. Then after the SNES generation finished and Nintendo was hit by a devastating software drought and fuzzy graphics, Playstation boasted 200 games, and showed off impressive CGI graphics in games like Resident Evil 2 and Final Fantasy 7, and went on to sell around 60 million units in 97, 98, and 99 effectively taking the crown that Nintendo had worn since the mid-1980s. And thanks to ongoing support, and the release of the new PS1 model, the Playstation went on to sell over 25 million more units in 2000 onward, which is when the Playstation 2 was the new hot system.

The 3DS is one of the most interesting cases of bad luck. The system itself was great, the features were excellent, but it also landed just after a massive anti-3D fear campaign started with sources reporting that 3D caused everything from eye damage to seizures and brain issues. So it might have been that the original price point was the correct one, but the unanticipated anti-3D backlash at the time really destroyed its chances. Nintendo followed through with the Ambassador program and the price cut, and significantly reversed the 3DS's terrible launch. It's hard to call the 3DS a sleeper hit though, as it was a system that was expected to sell better than it ended up doing, and sleeper hits are generally the opposite of that, low key release that weren't expected to be a very successful that turn out to be massive hits - some examples of this include Just Dance and Pokemon. A smaller example of a sleeper hit would be Phoenix Wright Ace Attorney, originally a port of a rather obscure and low selling Japanese GBA title, they shipped only about 60,000 units with no plans for more; but, a few months after release, word of mouth and internet humour drove up the demand for this, and it sold through the remaining unit quickly, and eBay prices skyrocketed; this led to more shipments and the franchise went on to sell 12 million units.

I have no idea what your finances are like, but if you have any interest in a 3DS it's pretty much now or never. The prices keep climbing for the hardware and a lot of the games.

Just about every 3DS model that isn't 2DS (the slab that can't fold) is about $150 USD and up online and in game stores. 

If I had more money and less hardware in my collection, I'd buy a replacement 3DS for my launch day model that is barely useable due to a crack in the hinge (one drop of about 6 feet but just general wear and tear after using the thing for 2000+ hours).