I have about a hundred hours in a 172, and a couple of hundred in a PA28 (owned the 140 variant, was checked out on the 180).
I have to say it's six of one, half dozen of the other. I happen to prefer the PA28 as I like low-wing better especially in turns. But the 172 is a fine machine. Of the two PA28s I flew, one (the 140) had the hershey bar wing, the other, (180), the taper wing. I think I liked the hershey bar variety better.
As for fuel consumption: about the same
Speed: about the same (not enough difference that you can notice on a short x-country)
Load ability: depends on the empty weight of the bird you're flying. More kit = less load. Basic VFR bird best if you need to carry a load. Both require careful W&B before taking off; the PA28 (at least 140) has a tendency towards nose-heaviness with two big lads up front and full tanks, in fact you'll be out of CofG range.
Short field: definitely Cessna.
Rough air: Piper.
X-wind landing: Piper.
Stodginess: about equal
Safety: both about equal, and fairly benign in a stall, and difficult (though not impossible) to get to spin.
Actually I like my current mount better than either: Beech C23 Sundowner 180. Very quick ailerons (in fact mine is one of the rare aerobatic-certified Sundowners). The Beech is stodgier in appearance, but has quicker handling especially in roll, and an even higher wing loading than the Piper, which makes a very stable rough air platform (at the expense of a highish 73 mph stall speed).
Anyway to sum it up, if your club has both, go for the one that's least popular, or more numerous. You'll have better availabilty, and about equal measures of fun, but to be safe, get checked on both. Variety is the spice of life.