Like everyone else I've been round the loop and there simply isn't a perfect solution. If you walk or do exercise on a warm day in just a cotton t-shirt it will get damp and that, quite simply, is the problem as there is no "magic bullet" solution.
My experience is that all "waterproof" solutions will retain more moisture than a non-waterproof solution and, what I think is a bigger factor, they will retain it for longer no matter what marketing claims are made. This means they can all become a little uncomfortable.
I've tried a lot of "solutions" and the one that works best for me is the surplus windproof smock with, when required, a gore-tex liner and in my case this takes the form of a surplus jacket.
The windproof smock isn't totally waterproof but when you wash some waterproofing for cotton into it then it becomes pretty shower proof, I've been out for several hours in heavy rain in mine with no leaks. As the smock is just cotton/poly it is also very breathable but, as I've said, this does not mean it will not get a little damp if you walk hard. However, when the rain stops I find that I dry out much faster on the inside in my smock than I would if wearing a totally waterproof layer. The smock itself dries very quickly. Now there are people on ebay asking a fortune for windproof smocks, for some reason, but if you bid carefully you can get new ones for £10 - £20. The new MTP smocks are very like commercial jackets with handwarmer pockets, mesh lining, pit zips and so on and I think this is a step backwards. The older DPM smocks are of a rather more simple construction and I think this is better for walking/fishing/bushcraft type situations as, apart from anything else, they dry a little faster than the more complex MTP ones.
When the weather is very bad I then add the gore-tex layer UNDER the smock. That way you retain all your pockets etc. but are now totally waterproof. Now in this situation you are back to square one in the sense that you are going to get damp on the inside but my experience is that I don't actually need to wear the gore-tex layer very often and it is rare that I need to wear it for long periods of time. When you think about it most people are not out in conditions where there is solid rain for very long periods of time. The smock dries very quickly and so almost as soon as the rain is over the gore-tex layer is off leaving just the smock and this promotes drying of any moisture gathered. The gore-tex layer is very light and easily rolls up and lives on top of my rucksack. I have 2 gore-tex layers one German surplus which cost me £13 and one British DPM layer which cost me about £25.
I'm out a lot, and have a lot of very expensive jackets, but this system is now the one I use through choice. The down sides are that you have to remove the smock to put the gore-tex layer on so that takes a few minutes and can be a bit of a chore in driving rain but I've found that using your brain (picking a lull in the rain, sheltering behind a rock etc.) easily solves this problem. Also most of the surplus stuff is only available in a range of cammo colours but in my situation I'm out 100+ days a year and probably see only a handful of other people and quite frankly I'm not much concerned about their opinion and I'm warm and dry.
I'm not claiming that this is a perfect solution, as I don't think such a thing exists, but it works very well for me and because it is relatively inexpensive I would suggest it is worth giving it a try. If you hate it then you can put the jackets back on ebay and get your money back.
Trousers, however, are another matter and I've not found anything to beat the Harkilia Pro Hunters. Until I discovered Harkilia I destroyed trousers at a rate of a pair a fortnight. The Harkilia have all the disadvantages of a fully waterproof layer in that they leave you damp and hold the moisture and so are not as flexible or comfortable as the smock/gore-tex solution in jackets but so far it's the best solution I've found.