Linniks, line-iks, leeniks… all three seem to have their adherents. I use the third pronunciation myself, because long ago (and long before I started using the OS), a friend of mine said that that was how Linux Torvalds pronounced it (and he was right, as you can hear for yourself). I figured that if anyone would have a right to say what the proper pronunciation was, it was the guy it was named after. But apparently many people disagree.
It’s a good thing that Linux zealots have a common enemy to unite them, or subjects like this could lead to holy wars. And Linux zealots already have enough fronts to fight holy wars on (KDE vs GNOME, emacs vs vi, ext3 vs JFS vs XFS vs Reiser, LILO vs GRUB, and the perennial favorite of which distribution is better, just to name a few of the most popular ones).
It’s spelled Linux, but it’s pronounced “Not Windows” — Usenet sig, original author unknown
If you listen to Linus closely, his name in Finnish sounds somewhere between lihnux and leenux. I actually now use the first of those two, simply because that seems to have become the standard pronunciation and otherwise people think I’m either talking about something else or don’t know what I’m talking about. (And I hate it when people don’t know what I’m talking about. 😉 )
Whatever works. People seem to understand me when I talk about it (as much as anyone ever understands me), even if they pronounce it differently, so I see no reason to change.