I love Internet memes. They're an endless source of often offbeat humour and a great indicator of trends in popular culture. I love the democratic nature of them as well, everyone can create a meme, even with zero knowlegde of photoshop or any other image editor.
Though relatively low tech Internet memes are a relatively recent phenomenon, I guess because social networks which really help spreading them is also relatively recent.
Some of my favourites include: First day on the Internet kid
Love the enthusiasm and naivety of this Internet newbie! Not sure if X or Y
Featuring Fry from Futurama with his squinty eyed suspiscious look. Dolan Comics
Often disturbing, badly spelt and poorly drawn Donald Duck comics. Except Dolan is a sadistic, rapist, perverterd bastard. X all the Y!!
I don't know why but I really love this one. maybe it's the extreme enthusiasm, maybe it's the way I always read it really fast in my head....
This site has great videos explaining most popular memes and how they originated: http://knowyourmeme.com