By asking the question, you obviously have doubts.
Blonde seems to be better for you, especially having blue eyes.
If the main photograph of you as a brunette is anything to go by, I'm afraid that it tends to make you look older - perhaps this was your intention - however, I feel that it was not.
Did you change because of hair damage caused by repeated use of blonde dye? This can sometimes happen.
Either way, it's your hair and your look, so the choice is very much down to yourself.
I guess this is not the answer you want... But blonde is better- that or go a richer darker warmer shade of brunette. That colour doesn't look like it knows what its doing.
Every so often I go brunette myself and always end up hating it! xx
I don't particularly like either if i'm honest. A nice warm shade of brunette would be favourable to what you have now, but the blond looked a little on the cheap side (i know it probably wasnt with maintaining it etc!) - if you insist on going back blonde i'd go a more honey blonde with nice high and low lights.