I have a 1997 Peugeot 306 turbo diesel, which at the moment have had no major problems with. Although the air conditioning has never worked, and never will because of the price of replacement parts, £400 for a condenser!. Still a very good car, can't really fault it.
I have an XTdt and it kicks arse... just had a prang with it and it was fixable.
It drives well (very like a turbo petrol) and has all the mod cons, including a temperature gauge and electric everything which is actually in fine working order.
The trick is to just simply look after it.
Treat it like a lady.
I purchased my 306 XTDT 8 months ago with over 110,000 miles on the clock.
Generally I am very pleased with handling and performance for what it is.
Apart from the front tyres warring on the outer sides of treads and the suspension and steering bushes going, the main problem has been with the passenger side electric window. This seems to work when it wants to, but in particular if it has been a hot day! I have found that if left in the shade it soon sorts it's self out...
...apart from yesterday when it decided to give up completely! So I tried everything from fuses (messing up the alarm in my lack of knowledge) to taking of the door panel to see if I could get to it. When it eventually became too dark to work I decided to tape up the open window with a plastic bag and gaffer tape, and give up to the mercy of my local mechanic. At this point a voice inside my head said "one last try", so I pushed the button and up the B***** went!!! – Well at least I leard how to disconnect the Alarm!