I always had simple (two buttons and scroll wheel) mice, but a few years ago a buddy got me Razer Naga for my birthday. It took me a while to get used to it, but I still hated it. Mouse was big and clunky (was awkward to hold) and I never used the 6 side buttons, they were more annoying than anything. Finally after 2 years the thing broke, everytime I would single click it would double click, so I went to get a new one.
I just wanted something simple, and after going to stores and trying them (honestly better than buying online) I found Razer Abyssus v2, cost me about $70 CAD, and it feels good and works well for what I use it for (League, RS).
Best thing to do is going to the store and trying them out for yourself. There are many types of size and grips (search on google), and some may be very awkward depending on the way you hold the mouse.