When (if?) Alfa comes back to the US, the model lineup will likely consist of cars that are quite new to even the European roads. I don't think anyone knows yet if the 159 (for instance) has any major reliability problems.
But: the 147/156/GT is generally regarded as a very reliable car amongst Alfisti here in Norway, but they tend to eat up the bushings a little fast. I'm not sure whether this is due to the engineering or the driving style you get when you sit behind an Alfa wheel
It's not uncommon to replace them after around 30,000 miles / 50,000 km.
There's been no recalls (that I'm aware of) on recent model years.
Also, (on Twinsparks at least) the cam belt is rather unforgiving if you don't take care with regular oil changes, engine oil level checks and watch your mileage. Cam belts should be religiously changed after a set period or mileage - whichever happens first. Around these parts of the world, it's three years or 37,000 miles (60 kkm). Other countries have different recommendations, mostly 3y/80,000 kms. The cam belt issue is not unique for Alfa anyway.
Another thing to watch for is the ball joints. For some reason Alfa decided to make the wishbone arm and ball joint into one single part. When the ball joint is worn out, you must change the entire arm. Unneccessary expenses in my opinion, but probably cheaper to make. Again, this is on 147/156/GT. I don't know what they did on 159 and Brera.
You've probably heard that some purists call the new Alfa engines for "GM engines". This is frankly a load of crap. The only GM thing remaining on a JTS is the engine block itself. Just that big slab of aluminium. Everything else is Alfa. There's not a single bolt in common on - say - an Opel and Alfa 2.2JTS head.
All Alfas are FWD these days, and they can be a little picky with regard to the tyres. There's a lot of torque coming down on the front wheels when you step on it. Grooves in the road (from studded tyres for instance) combined with the sensitive steering and torque means you should hold on to the steering wheel! With some types of rubber this is not an issue, but with others the effect is rather obvious.
I'm very satisfied with my 147. I've driven 20,000 miles without any problems whatsoever. And I don't take it easy when I'm out and about
If you maintain it the way an Alfa deserves, there's no reason to fear owning one.