Question about IE 8

I was using Firefox 3.5 until NickN said there were no real benifits to it. and switched back to IE 7.
Now for some reason or another, I avoided IE 8. I believe it caused me some problem that I've since forgotten.
Today, Youtube informs me that I must switch to IE 8 or back to FireFox,
Which is recommended?
And is there a problem with IE 8? (I know I did uninstall and go back to 7 for a reason, I just don't remember why after a year.
)
Now for some reason or another, I avoided IE 8. I believe it caused me some problem that I've since forgotten.
Today, Youtube informs me that I must switch to IE 8 or back to FireFox,
Which is recommended?
And is there a problem with IE 8? (I know I did uninstall and go back to 7 for a reason, I just don't remember why after a year.
