i have a 1986 vette (e) i have changed the valve cover gaskets at least 5 times.  is there another brand i can use or does anyone have any solution.  

Are you using a cork or rubber gasket? Also, are your valve covers stock or aftermarket?  

something is definitly wrong then !

are you sure the covers aren't bent ?

gaskets fit properly ? retaining nuts/bolts bottoming out before compressing gasket ?  
wrong gasket thickness ?

residue (chuck of old gaket) on head or cover ?

Have you tried applying silicone to both side of the gasket ?
remeber to let it "gel" for about 30 minutes before bolting down

just a few ideas

rick