A lot of my games lag or skip. I hear the same music played several times and the game becomes unresponsive for awhile. It usually only lasts a second or two but sometimes it is longer.  Also with one game, Super Mario Rpg, the game will freeze all together and the only thing I can do is to exit the page.  With another game, Paper Mario, the game randomly flashes and everything is black or I see through the graphics to the background. 
   Can someone please help me?  This has gotten really annoying and I have had to stop playing Paper Mario because it got too bad.

Well, I'm not expert on the RGR plug-in (Yet, I'm trying to learn but it'll be a while.) and I'm sorry to tell you this but all I can do is speculate at this point, I don't know anything about your computer or what browser you use, Is your Java up to date? Is there a new patch on the RGR plug-in? Maybe the file corrupted itself when you downloaded it and you need to remove it and repeat the process. But until I know more about your computer and your operating system there is absolutely nothing I can do to help you, Sorry man.

dryst4 : I've played Super Mario RPG before, and it was also glitchy for me. < A lot of times the game froze for me. I'm sorry that I think that nobody could fix that.
I didn't tested Paper Mario yet but I know that N64 games on Vizzed aren't always that good..

I have a few questions for you,

1. ~ Which other games where glitchy? Tell them to me, and I'll try out if they work fine for me.
2. ~ Which Browser are you using? And are you using the RGR Plug in or something else? (If you use the RGR Plug in, you always can try to install the Plug in again.)

Edit ~ Sadly Frodlex ninja'd me..

The Super Mario RPG ROM has a few common freeze points. The real common ones are around the Hammer Bros fight, Jonathan 'Johnny' Jones fight, and the Axem Rangers fight. Here is a thread with methods that help MOST people around the freezing.

https://www.vizzed.com/boards/thread.php?id=33680

For Paper Mario, it is an N64 game. The N64 ROMs are a matter of luck with compatibility with your graphics card. Pretty much, it doesn't matter which graphics card you have, there will be some N64 games that work with it, and ones that don't. This little graphics glitch you are having with Paper Mario seems to be that situation.

This is a situation where sometimes trying both emulators helps, also messing around with the Video plugins "found in the upper right hand corner of the game window" can help sometimes as well. I think I've heard that "Rice" works for a lot of people.

I personally rarely have problems with N64 games but I do know that some users report issues with Paper Mario. You could also try a different browser.

As far as Super Mario RPG goes, that's a Rom that doesn't play well with the default emulator for the RGR plugin. You could use the alternate emulator "Mendafen" and see if that gives different results. To use this emulator, just load the game like you normally would, then click the link in the upper left hand corner labeled "Play using Mednafen"

That emulator also supports full-screen by holding alt+enter on your keyboard with the game window active.

TornadoMudkip :
   Most other games skip or lag at some point but the worst one seems to be Breath of Fire.  I just re-installed my vizzed plug-in. I hope that works.  Also I am using Google Chrome.