I'm going to specifically comment on each car Sage has posted as well as adding choices of mine.
Mazda CX series = Great personality for what they are, spunky people carriers.
Mazda RX-8 = Should of never been built to look like that and have such a gutless engine. The build quality is top-notch, the interior is very good, but otherwise it feels gimmicky and soul-less. I did not have fun "thrasing it about" at all. Going from a 350Z to this and back again is like trading someone $100 for $5 and then asking for the other $95 back when you realize you've been screwed.
Civic coupe = I like the new one, I think it has VERY good personality. Even though I hate the new interior it has some serious space-theming personality. The saloon Civic is quite the opposite--its just an econobox.
Acura MDX = Nope. Great car, boring to drive.
Lexus IS = Yes and no, it has a snobbish personality...which isn't a good thing. Step out of a BMW 3-series into this and you're prespective changes dramtically. Infact the CTS has more positive sporty personality than this.
Infiniti G = So much personality it has enough left over to fund the entire Toyota lineup.
Infiniti FX = Duh. *see Infiniti G
Nissan Altima = Nope, a push button start and a CVT transmission remove what little personality it had. The previous 3.5 SE 5spd was a hoot--and it felt like it wanted you to push it. It's lost that edge.
Nissan 350Z = Duh. *see Infiniti G/FX
Acura RDX = Never drove it. Just based on visuals alone go read the MDX review.
Mazda6 = There just isn't a medium sized saloon that has more personality than this barring the Ford Fusion. The Mazda6 and especially the Mazdaspeed6 are just pure driving excellence. It acts like a puppy dog the first time you play fetch with it, it keeps bring you back the stick and wanting you to throw it again!
Mazda3 hatch = More personality than you can shake a stick at. Could possible fund the entire Kia lineup with extra personality. Saloon not so much--and my brother has one. The saloon HAS personality...just not nearly as much as the hatch.
Honda S2000 = Has more personality than the rest of Honda combined. I love them, they would be third on my roadster list behind the 350Z and SLK.
Mazda MX-5 = It lost all the personaity it had from the older model. Its bloated and fat.
Subby Impreza = Nope, its dazzling personality has been lost. You just simply can't change the TYPE of car it is and expect it to even have any of the orignal's personality. Epic fail.
Mitsubishi Lancer = All new models OOZE personality. Just look at that grille! It wants to eat your children! I love it.
Mitsubishi Eclipse = It hasn't been good since the GSX. The GSX was the baby GTO Twin Turbo AKA 3000GT VR4...it was just flooding with personality...and then they killed it...and now killed it again.
Nissan Versa = Nope, nothing here but boring practicality and reliability.
Honda Accord = Gained small personality points for the new exterior (even though I don't prefer it) but loses some on the interior...and to me it feels more "soft" than the previous model.
Honda Fit = Fit FTW, enough said. Drives like a DREAM, honestly it is epic good stuff.
Mazda5 = Could you ask for a more sporty people carrier? Has more personality than all of Japan--I'm serious its the perfect car minus a huge turbo.
Mitsubishi Galant = rubbish all the way around.
Nissan Murano = Plenty of personality. It has chrome teeth!
Subaru Legacy = Took over what the previous Impreza had and added more.
Subaru Forester = Could it get any better than the XT model? The entire model range of the Forester is just awsome.
There may be a few more but I feel it is obvious that Japan is in a null stage right now. The 80's and early 90's Toyota, Nissan, and Mitsubishi were full of personality followed by Mazda and Honda. Now they're getting on the right track--and they are putting out some models that would of surprised you about 10-15 years ago--notably the Mazda5 and Honda S2000 (now dead

).
[globally]When I narrow it down to hatchbacks for instance when I think of personality I automatically jump to--drum roll please--the
Volvo C30. It has all the right kinds of personality. And in terms of mid-sized saloon cars the
Mazda6 takes that crown. Crossovers? The
Ford Edge does it for me in all the right places. SUVs--its a bit more difficult since they are in large the same thing all around, but the first one that pops into my mind is the
Subaru Forester. Its just brilliant. Executive saloon cars--
Mercedes S-class and for no other reason than its the daddy with more trinkets and gadgets than James Bond...and that's cool...
and cool is a personality trait when its spoken in the same sentence as James freaking Bond.
That being said, Mazda without a doubt is one of the most-spunky car companies out there. They just seem like they don't give a damn, do what they want to do, and don't care if you don't want to buy it. They're fun to drive, fun to look at, and best of all are easy on the wallet and return those happy feelings you love.
QFT - Quoted for truth. Mazda just hits the target pretty much across the board. If the RX-8 and MX-5 were just a smidgen better they would be included on my positive personality list.
Bah. The RX-8 is a much better car than many people give it credit for. Drive one sometime. And don't just putter around in traffic and complain about no torque.. I mean really drive one. It's terrific.
I have "thrashed one" and I found it quite lacking in the fun department--especially because it was right after I drove a 350Z. That's like getting out of a BMW and getting into a Kia. Sure the Kia is probably a good car...but come on its not a BMW.
It invariably looks like a three-dimensional representation of an orgasm.
It is painted in a colour that sears your retinas.
It makes you drool like a pre-pubescent schoolboy.
Speak for yourself. The only Italian car I see with personality is the new Fiat 500 and anything with a Pagani logo. Oh, and ONE Lamborghini--the mad LP640, which is quite possibly the best Lamborghini ever. Ferrari? *yawn* What was I saying? Ferrari is way to busy trying to build surgical tools for a race track to even think about personality. And it took how many years for Audi to put the personality BACK into Lamborghini?
It inevitably looks like a taxicab.
It is silver. Or dark gray. Or silvery gray. Or dark grey-ey silver.
It makes you yawn.
I'm going to list a couple of German cars that prove your statement false.
Audi RS4
Audi RS6
Audi R8
BMW M3
BMW M5
BMW M6
BMW Z4
Mercedes AMG anything
Mercedes G Wagon (ultra pimp)
Porsche ... erm everything except the Cockxster...I mean Boxster.
Opel Speedster VX220--not really German lol
Mercedes-Benz do make sobering cars, though. I'll agree with you on that one.
I haven't driven a new C-class yet but I can tell you that you need to drive an AMG Merc. If you drive an AMG and tell me it lacks personality then you are brain dead. The CLS63 has to be one of the best things from Germany right now, it just hits all the targets dead center. I drove one, and I almost literally *ahem* got excited (same feeling as when I drove an SL55 AMG). And I didn't think that was possible...much less twice.