2009 LT finding source of oil leak/seepage under engine

While doing an oil change on my 09 Aveo LT a few days ago I noticed that there is an oil leak/seepage underneath the engine specially under the oil pan and under the oil filter area, pictures are below. So far there is no dripping of oil onto the ground underneath the car so it is not a major leak, but it seems to be building up a layer engine oil film under the engine in these areas and it is an going leak since I can wipe this oil film of with my finger. It has been going on for a while undetected since, like I said, there is no actual oil dripping on the ground below the vehicle, but I am trying to find the source of this leakage to fix the problem. Some ideas (more like guesses) are that it could be the valve cover gasket or the oil pan gasket although I don't know if either of these could cause the oil to be present in these areas or it could be coming from a different place altogether that might be known to be oil leak sources Any ideas or suggestions would be welcomed. Pictures of the top of the engine/valve cover are also included.

Looks like a seeper alright. What I usually do to find leaks is I clean the entire engine with detergent and a high pressure sprayer - so everything is clean. Then after a bit of running using a flashlight I look all over to locate the origin of the leak, usually just follow the fresh trail UP to it's leak spot. Otherwise finding it in the muck is about impossible, and any job is always ten times harder in layers of grease to deal with. Most likely the valve cover gasket, but just throwing a guess.

By the looks of the top picture it does look like you maybe leaking from the valve cover gasket. Not a hard job to do and the gasket itself runs about $20 to $22 at Autozone. But I would double check just to make sure that's the case.

Thanks for the input guys, yea that is also my main guess as well. I am going to be cleaning the engine and doing the valve cover gasket job in the next few days, as soon as it is done I'll post an update and results. Hopefully this is the source of the oil seepage.