The easiest way to stop it from leaking is to put less in it.
Where is it leaking from? If you can't tell get some simple green and go to town on the engine, once it is factory spotless take it for a drive and look for oil. Mine mainly leaks into the air box, the little bit that leaks out of the oil cap dries on the valve cover before it can run down and drip, so at least it is self contained and does not leave spots.
Are you 100% it is leaking from the motor? The manual transmission takes engine oil, the transfer case takes automatic transmission fluid, and both axles take gear oil.
the Fel-Pro reusable rubber valve cover gasket is a worthy investment, as long as you combine that with maintenance on the PCV and/or orifice and vacuum lines.
+1 on mike134's advice.
If there is too much pressure inside that cover... it will blow out somewhere. Because our engines are not exactly straight and tilted to the rear (and its impossible to see back there) it will force itself out back there and you will never be the wiser without a 90* dentist mirror
(could be worse, these pressures have been known to blow that pressure and oil right onto your air filter). Since you gotta take the cover off - clean it up real nice... remove baffles and clean up nice. Make sure those gaskets are in tact and just get new valves and grommets. Not expensive and should be done if never done before.
Stop whining about the 'ride' - If your YJ ain't wrangling your soul free, then might I suggest you buy a stationwagon... at least you can fit all your bull**** in the back.