I have to agree with the other guys. The easiest thing would be to use Phoenix, but if you want to do the hard work yourself then I would say it's relative easy to use OpenGL and SDL combined.

As soon as get a hang of OpenGL it's really easy. The only real tricky thing is to setup OpenGL, but this is done by SDL already
There are some OpenGL demos with JEDI-SDL (well there used to be, don't know about the latest release). And then there is ofcourse the NeHe tutorials that covers OpenGL. You probably wont have to read more than 5 tutorials or so to be able to make some basic 2D game.