Maybe it's because I do most of my running in the west of Ireland which does have a certain reputation, but I have two rain jackets which I use dependent upon how hard it's raining.
The first is a Montane cycling jacket. It's breathable, tissue paper thin and will only keep very light rain off. I wear this on warm evenings when if there's gentle rain, or it looks like it's going to rain. I did wear it once on a 200km sportive cycle ride which was torential rain from start to finish. I was soaked after about 15 minutes, but in fairness to the jacket, I was still pretty warm as most of the rain still ran off the jacket and I was warm and wet underneath (oh err missus).
The other one is a much cheaper, non breathable Ron Hill jacket that does a much better job at keeping heavier rain off and although it's not breathable, does have good ventilation. I wear this if the weather's cold or if it's heavy rain. I find that I don't get that sweaty underneath, or not enough that bothers me (the first thing you're going to do after a run in the rain anyway is have a hot shower).
Alos, it's worth noting that although it's raining reasonably heavy or I'm feeling a bit precious, I wouldn't even bother wearing a rain jacket.
If you're looking for something to wear in the wilderness, I'd strongly suggest you look on some of the fell running forums as that's a lot more specialised requirement than a 15km run around the local town with some mates on a wet evening. They can probably also give you advice on what to carry in terms of survival gear as well.
