You should also look into which tense you use. I've been finding that first person is great... but becomes very powerful if you opt to write in the present tense. Then, instead of relating a tale, it's happening right here, right now.

It puts a limit on how you deal with other people in the story, which can be a fun challenge for the writer, because their thoughts and actions need to be expressed as the POV's perception of what happened.

Of course, one can switch back and forth... and even use a different POV for the supporting roles... but in that case, don't do it except at major break-points... like chapters, or scene changes.