Like I said, it ends up being one of those "if ya like it, ya like it" things. If you HAVE an optical mouse and like it, use it. If you don't have a mouse and are asking for suggestions, then I am going to tell you to look into laser mice. Maybe it's just me, but....oh well. To each their own, I guess. It's more or less, you get what you pay for. Maybe I'm so biased because I've never had like a $50 or $60 optical mouse in my hands. Only cheaper stuff.
EDIT: ^^ I will make the MX518 an exception since I have used that (parents are using that now since I have been using mostly my laptop and have a wireless logitech nano) and actually liked it. It is a great optical mouse and I would recommend that. I researched quite a bit before I originally bought it. Most laser mice were really spend so I had to go optical at the time. TBH, the pricepoint of that mouse is what is most attractive. It might not be top tog, but in the bang-for-buck category, I think it takes the cake when NewEgg has rebates or good deals on it.
Another thing to consider though is that optical mice chew through batteries faster than laser mice, IIRC...so if you go wireless, keep that in mind. Someone correct me if I'm wrong on that, but I remember going with a more expensive laser mouse to save on batteries when I got it for my laptop.