Well going purely off of hindsight and not hypothetical...
Pardew had a season and a bit, the team broke spending records in League One and had the strongest squad on paper by a distance, we missed out on the play-offs by 7 points, with a 10 point deduction. We had the leagues top scorer, the 2nd best scoring record and the 3rd best defensive record and didn't manage promotion. Slightly unfortunate to not make the play-offs but still, not really good enough. We then started the next season poorly and were lulling around by the bottom of the table.
Adkins has had two season (ignoring the PL so far), earned successive promotions with an incredible home record, and a style of football revolutionising the team and earning rave reviews.
Pardew did not do badly for us by any means, and helped hugely to build the foundations for Nigel to take the reins, and has gone on to have a very good season at Newcastle. But there's no competition for me.