Painting - Paint sprayer vs. brushes for trim

I am trying to paint the trim in my house. I have been trying different brushes, but always seem to end up with brush strokes, which look bad. I am on the verge of buying a paint sprayer, but am wondering if anyone else has had any success? I want to use a semi-gloss to high gloss paint, and have tried brushes from the cheapest to the most expensive, and all produced brush strokes.

With proper prep, paint, right size tip and experience, spraying trim and woodwork can be as smooth as porcelin, but without the experience I would not suggest it, it can also create a big mess, if you are wanting to try it I will suggest lots of practice on hobbies or crafts before running inside and spraying. A reversible tip (depending on the type of gun) is also handy, for a beginer I would suggest useing a 4:10 reversible finishing tip. Reversible means that if it clogs, you reverse it and shoot the clog out, return it to foward position to keep spraying. This is for airless only.

What type of paint are you using? Latex tends to leave brush marks more so than oil. It is hard to brush smooth surfaces such as trim and leave no brush marks. To get them to a minimum, use a quality oil based brush (like Purdy), a quality oil based paint, thin some of the paint with about 1/4 thinner to 1 part paint, remember, you will have to apply a thinner coat of paint (or it will run), thus more coats. It just take practice, hands down, that is why people hire the pro's :)