......It would be nice to get to shoot an assortment of guns before I decide, but I don't have that luxury.
And I think that the opinions of probably some great shooters giving me advice on what they like can help me make a decision.
That is always a problem, isn't it. It's not so bad in areas where we enjoy one of the rare commercial rent-a-gun ranges. But I understand that there's nothing like that in Ontario.
If you're considering getting into one of the shooting sports then one way to get to try some guns is to buy a couple of boxes of ammo and attend one of the events as an observer and helper. Trust me, just show up for registration in the morning and indicate that you're interested, are willing to lend a hand for the day and that you're hoping to get some advice on the guns and gear as well as maybe try some of the guns. By being there, being interested and being willing to help with patching and scoring and even with the tear down at the end of the day I guarantee you'll have the guys all standing around pushing their guns into your hands to try. The ammo you bring is to offer to use or replace that of the gun owners. But more than likely they'll wave it off and tell you to save it for your own gun. But they WILL appreciate the offer.
If you do this at things like an IDPA, IPSC or even casual club meet you'll get to try a whole range of guns. At least this has been the case when I've been at events and a newbie shows up with the same sort of intrest and that hang around for the day or at least much of it. It'll also serve you as an introduction for the sort of events that can be enjoyed with a handgun or two and guide you as to the sort of gun you would like.
It may leave you with little to no experience with revolvers though. But you'll get a good grounding in the more popular semi autos. And as those of us with handguns know it's like popcorn. You can't shoot just one....

So eventually you'll get to try a couple of different revolvers.
So where's this leave you for now? As you've seen in the replies any of the guns that are popular will easily shoot better than the big majority of shooters can manage. So it makes buying your first gun not so much finding one which is the most accurate as it does one which YOU can SHOOT the most accurately. Handguns are not like rifles in this way. With rifles if you're like many shooters you're used to shooting from a rest at the bench. Or you brace against a tree if hunting. The closest comparison between rifle and handgun shooting is the free standing shooting used in metallic silhouette events where there's no rest and no sling allowed.
One of the big things with handgun shooting is learning to avoid a flinch. From there the other biggie is learning to hold the gun with a steady sort of grip while moving ONLY the trigger finger. Both of these become somewhat problematic for many shooters. Your rifle shooting will help but with the rifle your shoulder takes the brunt of the recoil. With a handgun it's all in the hands. So even if you're a good rifle shooter for standing freestyle it doesn't automatically mean this will translate to your handgun shooting. It may, but don't take it for granted.
Glock, M&P, CZ, Sig, S&W, STI and Ruger are among the mainstream guns which I know shoot well. Most are pretty similar other than Glock which I find tends to have a fat grip and a slightly more swept back grip angle. You may not be able to shoot them but you can certainly hold a few in the stores. Try to find one which folds into your hands well and where you can feel even pressure reflected back into your grip from ALL around the gun's gripping area.
Some of the guns mentioned so far are a rung up the ladder better at producing tight groups. But the mainstream guns that are generally popular are still more than capable of producing 2 inch or better groups at 25 yards out if the shooter can hold them that well. Few can though. Which is the reason some of us are suggesting that you just get one of the basic mainstream guns for now. Simply put the vast majority of us can't and won't see the difference between shooting a basic CZ, Glock or M&P vs shooting one of the uber accurate Sig P210's. The difference in the two guns gets pretty much lost in the "noise" of our jiggly nerves and poor eyesight. If it turns out that you are Olympic Team Canada fodder you can always move up to the fancy target stuff later on. You may be looking at your FIRST handgun, but it most certainly will not be your LAST one.
To do this well check out this video for the popular two handed isosceles stance and grip. If you don't hold the gun correctly you won't know if it fits you well. With care you can shoot ANY handgun well. But the ones that fit you like a well broken in glove will make getting to that point a lot easier;
http://www.youtube.com/watch?v=DDZDttBfock
Finally if you can't bring yourself to buy a .22 as your first handgun then by all means by a 9mm. I say get a 9mm as it means you can buy more ammo and get more trigger time with the cheaper to feed 9mm than any other caliber. And more than with rifle skills shooting a handgun well is very much a perishable skill.
Among the .22 semi autos the two biggest and bestest performers are the Ruger Mk series and the Browning Buckmark. Both are very consistently accurate, popular and reliable. If you are looking at the Ruger option for a .22 I'd strongly suggest the 22/45 model that has the switchable grip scales. The basic MkIII is a fine gun but the Luger like swept back grip angle is more at home using a one handed side on bullseye stance than it is for two handed action shooting. Which is fine but as a trainer for a center fire gun you are better off for now sticking to a similar grip angle as you'll use later on. And both the 22/45 model and the Buckmarks share that angle. The cheaper one piece frame 22/45 with no way to add grip scales is just too skinny. I'm not sure who they are supposed to fit as they don't fit anyone's hands well that I've ever seen.