I love my FRS, but I also have a truck in case I need something more practical. If the FRS is your only vehicle, you may regret it a bit. If you're only concerned about getting something fun, then you really only have 2 choices, the FRS or the Miata. Unless of course you buy used and find an S2k. There's a lot of bad stuff I could say about the FRS, but the positives more than make up for it. Yesterday, for example, I went on a 2 hour drive to get beer directly from the brewery, instead of the liquor store that's less than 5 minutes from my house, just because it's that enjoyable to drive. And, depending on if you want stick or auto, both transmissions are fabulous. I test drove the manual and it was amazing compared to my old Mazda 626. Ended up buying an auto because my ankle is pretty fucked up and on some days it's difficult to operate a clutch pedal and I don't find I'm missing anything. The only time I've even felt a little bit bummed about it is when I'm at a meet and someone decides to shit talk me about it. If you do decide to go with an FRS, wait until the 2017 is released (assuming you're not in a rush to buy), it's going to be the refresh year apparently. And it's a win-win if you wait, if you like the new body, buy it, if you don't, the old body will be heavily discounted I bet. Also, another important thing to keep in mind, is that the FRS is extremely barebones, unless you get a limited edition. I'd look to a BRZ if you care at all about things like dual climate control and heated seats.
Really digging the iM. Haven't driven one yet, but it's the Toyota Auris(?), basically just a 5 door Corolla. You'll get a billion miles out of it and they're specced pretty well.
Don't know much about the Ct200h, but I do like how they look.
Judging by those 3 you mentioned, you're looking for something a bit sportier? There's a bunch of oddball cars I'd like to get, but at this point, being real, I'd like to move on to a 2015+ WRX. Function, form, the whole package. When/if I move on from the FRS, I'll be looking into either a new Miata or a WRX. Maybe even an S2k if I can find one at a reasonable price.