yes, it is far closer to PS2. Hence the many ports both ways...

After all of the comments, I decided to do a bit more number crunching. One thing before we begin, though: you have to remember that sales do not all just happen at once, nor do they happen with an even distribution rate. There are three basic models for system sales you see: normal, market leader, and disruptor. Each has a general trend:

Normal: sales start low, peak early, then drop off quickly
Market Leader: sales start average, peak early, then drop off slowly
Disruptor: sales start low, peak late, then drop off slowly

The Game Boy followed the disruptor sales model, while the Game Gear followed the normal one. Ergo, the Game Gear's peak year was not very long after its release: around 1993 or 1994, in fact. By that point, most of its sales had been made, while the Game Boy was beginning its peak as well (in spite of a late start; disruptors always start slow and gain momentum). Since the disruptor sales model leads to trailing sales which don't die off fast, however, this meant that the Game Boy line had not yet sold anywhere near the volume percentage-wise of its lifetime sales as the Game Gear had. A reasonable estimate would be that the Game Boy was around 30 million units sold in 1994, while the Game Gear was close to 9 million.

That puts it at about 23% Game Gear/77% Game Boy for hardware. Software-wise, the Game Boy was doing better than the Game Gear was, which would put the ratio closer to 20% Game Gear/80% Game Boy. So, checking the math, I concede that it's not a perfect parallel after all. The Game Gear did in fact not manage to match the Game Boy in its peak year at quite the same comparative level as the PSP has to the DS.

1) RRoD - Microsoft had it in the bag, but then they screwed the pooch with this one. In my assessment, RRoD is directly responsible for the slowdown of sales that let the Wii pass the 360 in less than a year. That was a huge blow to how people perceive the 360, and I think may ultimately have shifted favor to support the other consoles enough to tip the scales so that 360 ultimately ends up last in this generation.

2) Virtual Boy - even when I was 10, I was able to tell that this looked stupid. It was a failed system, but at least Nintendo was able to recover from it and move on to things like GBC and GBA, which is why it comes after RRoD

3) Sixaxis - no rumble, and motion controls that are going to let you do what? steer a car, balance on a rope, and what else? This was a slapped on reaction to the Wiimote and NO other reason to be implemented.

4) UMD - You think that Wiimotes eat through batteries? Great, it can play movies that are specifically designed for that system and can't be watched on any other device.

5) $599 PS3 - Sony would have done better to launch it at a loss to start with. they managed to recover from it.

 yea it's much worse than RROD.  Look at 360 sales, they are a pretty big improvement over xbox sales so saying RROD is one of the worse mistakes in history is totally wrong.  As bad as RROD has been it's not a fatal mistake, PS3 being $600 was a deadly mistake for Sony.  Nintendo using cartridges was a terrible mistake.  Sega's whole plan with the saturn was a huge mistake.  Sega 32x was a huge mistake.  Virtual boy was a huge mistake.  

RROD doesn't belong in the same list as any of those, despite RROD Microsoft is doing pretty well.  People will not look back at the 360 and see huge mistakes like they will with the PS3, N64, sega saturn, 32x, virtual boy etc.

Alright then. Well anyway, we all agree that the PSP isn't a failure so the inclusion of UMD didn't mess it up too much. I guess we can get back on topic now =)

The biggest difference between GG and PSP's performance vs. their competitors IMO is that the PSP is not dying. The GG was only a market force for a relatively small part of the GB's lifespan.

 Sales aren't down, sales are still getting higher for 360.  The problem they have is that the PS3 sales increased much more than the 360 sales did, same with the Wii.

i think sony should erase 2007 from their calendar, that was the worst year --for them.