I've ridden lots in dressage, all purpose and (to a lesser extant) close contact saddles, and have coached several beginners. I agree that there is a "right saddle for the right job", and I wouldn't dream of jumping a 4 ft course in a dressage saddle, and I wouldn't look forward to trying to ride advanced dressage in a close contact saddle (you could, but it woudn't be very comfortable). That being said, I think that there actually is a place for an all purpose saddle. I have found them to be very useful for introducing some horses to both dressage and small jumps, and for taking out on trail rides. I have also found them useful for beginners, both for basic dressage and going over small jumps.
I have ridden in many higher-end saddles (I have two Passiers, and I love them!), but dollar for dollar, I really like the Wintec saddles. Of course the most important thing is that the saddle needs to fit both you (note that English and Wetsern seat sizing is different) and your horse. That being said, for starting English riding, and going out on trails, I would highly recommend the Wintec 500 or the Wintec 2000, both all purpose saddles. You can also customize the saddle a bit by changing the knee blocks (they come with a set)/ thigh blocks (you have to order those), and by changing the gullet size to suit the horse. They don't necessarily work for everyone, but I have had really great experiences with them. They are also relatively inexpensive, and often much nicer saddles for the price than you'd be able to get in a leather saddle. If you later specialize, then you can get a saddle specific to one discipline. You could also try the Wintec Pro Dressage or the Wintec 500 Dressage. I know that it is a Dressage saddle, but the seat is very similar to the all purpose, and it allows you to rise with a slightly longer leg than the all purpose, but also accommodates a shorter leg. Don't be afraid of the fact that it is a dressage saddle. A friend of mine that I coach has a Wintec Pro dressage, and basically just trail rides with it (sometimes up a mountain), does some flat work, and occasionally goes over the odd small jump/cavalletti (less than 2ft, any bigger and she'd need a different saddle), and absolutely loves the saddle. That being said, I'd try an all purpose first.
I completely agree with Speed Racer, that the best thing you can do is ride in several different saddles and see what works best for you and your horse. Alwaydbehind has a great point that what works for one person may not work for another. I would add, that when you have found one that you like, if possible before you buy it, you might want to have a lesson in it to get a second opinion. You want to make sure that the saddle will help you ride better and isn't encouraging you do to anything that isn't helping you do that.