These cars all directly compete - so the compare tools are somewhat silly. Still, Mazda's compare tool is by far the best one out there, and doesn't beef up anything...just lists EVERYTHING for each car. It's here:
http://mazda.ca/MciWeb/compareVehicles.actionFor the record, my brother has a 2007 Mazda 3 GS, my MIL leases, so she's had 2006, 2009, Mazda 3 GT, and and 2012 Mazda 3 GS-Sky. I have a 2010 Corolla. My good friend has a 2012 Civic. My other good friend has a 2013 Focus SE sports package.
First question: Buying or Leasing? This should be at the forefront of your decision. You're not looking at base models here, so resale value should matter, as should long-term dependability. Ford has made strides in quality recently, but they're still not really up there. I would highly recommend an ECP, for as long as you can go. In opting for it, they tend to reduce the price on rustproofing, too. It may be a wise investment, but it is like insurance - you pay for it hoping to never need to use it, but you'd be happy you have it there.
None of these cars are amazing sports cars. I, personally, love the drive of the Focus...way more than the Mazda. I find the Skyactiv treatments have made the Mazda 3 slightly more numb, but I haven't tried the 2014.
The Civic is an amazing car, I'm not quite sure why you haven't considered it - but you should. Great value, not a bad driver either.
As much as I'd like to see the Corolla in this, I wouldn't include it either. It's a boring drive, now with CVT, and I'm concerned that since it's been built in Cambridge, it's not the same reliability that we had expected. My tranny now fails to engage 4th gear until the car is warm, for example. Thankfully, I have a 7 year ECP and it's all covered. See my point?
The Forte redesign did some nice things. In fact, Kia has made strides with their reliability, too.
I don't think you can go wrong with any of these cars. They'll all be within a very similar true price to own range. The truth is you have to spend one day and test drive them all back-to-back, and let the dealers know that you're prepared to buy (i.e. follow up with their stupid giving in of your driver's license and credit card). Until you sign paper work, you have no agreed to anything, so once you get their final price offer, you say "I need time to think about it, I'll be back" and walk out. Before you do, ask for their offer in writing. Offers remain valid until they provide you notice of it otherwise...so if you come back in and say "I accept," they have to honor that original price. The caveat is if they say "sorry, walk out and this offer expires" then you may not get it again...but they'd be stupid not to honour it if you're there willing to buy the car.
Here's my cons to each car so you know what to look for (and whether they bother you):
Civic - I'm not a fan of the dashboard, and it's not the sportiest of drivers.
Mazda 3 - I HATE the driver's seat cushion. It's flat, and the bolsters make it more difficult to enter/exit the car. If you're not arthritic like me, that may not bother you, but those seats really kill my butt. I also find the interior to be laced with plastic. My brother's 2007 does not have any issues, but before his ECP expired, he took it to the dealer and they reconditioned the car to be like-new (except for paint). I.e. they replaced the sunroof, power steering, transmission parts, etc. Not that any of those NEEDED to be replaced, but they were as a goodwill gesture to ensure longevity.
Focus - I am wearing about durability of interior pieces...and the DCT (transmission jumpiness). The infotainment buttons are very, very non-intuitive, so make sure that doesn't bother you. The upgraded MyFord Touch isn't any better.
Forte - I really like the 2.0L engine, but it does use more gas than I would like. The car is big, relatively speaking, and probably won't return the best fuel economy of the bunch. The steering is also very, very numb (but I drive a Corolla, so I can't complain too much - but you specifically mentioned that you want the car to be sporty).
I'm assuming you want a sedan, not the hatchback...since the Forte, at the moment, only comes in a sedan.
If it were me, I'd actually probably get either the Civic or the Focus - but look at the Focus SE with some options - save a few grand (or put it towards ECP) and it will have everything you need. The way I packaged it, it's $21,577 (with PDI/Freight, but excluding tax). The Titanium trim doesn't add a heck of a lot, and comes out to $26,078 for the base (no other options selected).
The Civic is always a solid choice, the Ford has become quite the contender (and I historically hated Ford), and Kia is becoming a great contender. As much as everyone here loves the Mazda, it's sporty, but still feels cheap to me and I hate the seats. STILL, if you're after sporty/peppy as a primary concern, then the Mazda 3 GT is the way to go with the 2.5L skyactiv engine.
It's not hard to test-drive 4 cars in one day...just do it and decide for yourself. Back-to-back.
...and don't let dealers up-sell you on things you don't need. The titanium trim really doesn't add that much for the price - Ford's option packaging is very, very good.