The 146 is a lot of car for the money. I bought mine 3 and a half years ago when it was less than 3 years old, and it cost me only £5k, was in mint condition, 35k miles and had a full service history.
It's got great spec - air con, electric windows, alloys, electric sunroof, Kenwood sound system, twin airbags, etc
It drives well and the 1.8 Twin Spark is pretty punchy - needs to be revved high to get the best performance out of it. As long as you keep the revs high you can have a lot of fun on windy country roads. Handling is good and the brakes have plenty of stopping power. Fuel economy is fine if you cruise, quite thirsty if you push it. I get 300-350 miles on a tank.
It's practical - fairly short in length so not too bad to park (though has a pretty bad turning circle) but has a decent boot and will take 4 normal sized people, though not with much to spare. I'm 6'2" and wouldn't want to be any taller as head brushes the ceiling when driving, even with the seat at it's lowest.
It's a bit unusual - I was originally considering a Golf until I walked along my street one night and counted 17 Golfs on a street of 80 houses! Looks good although beginning to show it's age. There's some nice little touches - the boot lock is hidden under an Alfa logo on a hinge.
The problem with this car is that while it's a great design, they just don't appear to have built them properly.
There's the niggly little things - the front wheels seem to need regularly retracking or you get excessive tyre wear (I wore out a pair in under 2000 miles). The brake calipers keep coming out of alignment and rubbing on the wheels which causes a teeth-grating high-pitched metallic sound which kicks in 5 minutes after you hit the motorway and mysteriously vanishes 30-45 minutes later (have had this 'fixed' on 6 different occasions now). There's an airbag warning light on the dashboard which keeps coming on - have had it turned off 5 times and told that there's not actually anything wrong with the airbag but it keeps coming back on. The drivers seat height adjustment isn't damped properly so if you leave the car for a couple of hours the seat rises up to maximum height. The radio goes dead every now and then, the garage can't find a loose connection but it seems to come back on if you hit a bump - I've actually resorted to briefly driving on the motorway rumble strip before to kickstart the radio, which might explain why my front wheels need retracking so often.
And then there's the major things. My car needed new front suspension struts after less than 50k at a cost of ~£500. A couple of years ago it just wouldn't start one day - wouldn't even turn over. This was a recurring problem for 6 months. First they replaced the central locking system. Then they thought it was the immobiliser and did something to that. Finally they replaced all the wiring in the Engine Control Unit and that seemed to fix it, but after 3 visits, 6 months and well over £1k.
And the dealerships are awful. As above, they often seem unable to fix a problem. They're extremely expensive - even a service where there is nothing broken seems to cost the best part of £500. They're incredibly rare - a couple of years ago there wasn't a single official Alfa dealership within the M25, although there were some Alfa specialists. They've fixed that but some of the new dealerships have no experience of Alfas. Customer service is appalling. They never call you to tell you when the car's ready - you have to call them, and most of the time it's not. Once I booked my car in for a service and took the day off work to drop it off (I had some other things to do!) only to be told when I got there at 8am that they had no record of my booking. I'd driven 20 miles to get there as it was my nearest dealer and told them that if they didn't find space for the car they'd lose me as a customer. The guy just shrugged!
I'd like to think I'm just unlucky but I'm not so sure. A taxi driver told me he used to drive a 146 - one day he drove away and his bumper fell off, another day he closed the driver's door on getting out of the car and it fell off! A friend drives a company 147 and has had similar dealership problems to me, plus the same old airbag warning light problem. Another friend bought a new 145 when they first came out, the engine blew up and needed replacing (under warranty) after less than 5k miles, he had a new gearbox at 10k miles, and then gave up.
If you're thinking of buying an Alfa - any Alfa - think very carefully about it. Find out where your nearest dealer is and what they're like, because you may be spending a lot of time (and money) there. If you want something a bit unusual and a bit more fun than the your run-of-the-mill Focus, Astra or Golf and you don't mind a bit of extra hassle then an Alfa could be the car for you. If you want a trouble-free driving experience and get worried about things like squeaks, rattles, things falling off and warning lights coming on, then I suggest you go and buy something German or Japanese.
As for me, I finally gave up and traded the 146 in for a BMW. Was sorry to see it go, and I get a flash of nostalgia every time I get into my new car and instinctively reach for the lever to lower the seat before discovering that (amazingly!) it's still in the position I left it in...