Being who I am with technology I couldn't bare to see Microsoft die, Apple does not have a Tablet PC, and probably never will. If there was too much sompetition in computing, it would be harder for gaming, as some companies would favour one over another, and it would become like owning a console (of which I own a 360 wii, and ps2 because of games not being released on all)... Also, you cannot upgrade a mac like you can a pc. I like being able to custom build my own computers, can't do that with a mac. If mac had a bigger market share, Apple would lose their ability to market as being virus and hacker proof, as they are just as easily hacked and infected as PCs, except not enough people use them to make it worth while. Linux is the real answer, if you know what you're doing, Linux can run any program for windows or OSX, and you have to be knowledgable with linux, and a complete idiot all in one to be susceptible to the only virus made for Linux, not to mention, even then, viruses can't really do anything harmful to Linux based on how it is set up. You can get a virus scan for Linux, but it just a waste of space... Any virus that can affect Linux needs user permission plus a password to do anything, including be put on the system, unless the user is running as root (but who does that anyway).
I don't ever want to see Apple have a bigger market share, their computers would just become like iPods, an overly popular product that is inferior to other things on the market. There is nothing amazing about a mac, it is also not inferior either. I would rather a Zen than an iPod, hence I have a Zen, which is much more user friendly, and tend to last longer.
For me though, Win98 was the height of Windows.