A line I just started using and love is the Royal Wulff Triangle Taper line. I use it on my 4wt for Bluegill and Crappie and love it so far. It probably casts better than any other weight forward line I've used. Still haven't tried Cortland 555 yet though. Still, if you are looking for budget line, this is not it. Its anywhere from $50-60 depending on where you look. I picked mine up on eBay for about $30 though.....Try there for decent lines for cheap.
Now, a decent cheaper line I've used in the past was the Cabelas Prestige lines. They run about $25 and you can get them in WF or DT from 2-10 wt lines I believe. Now they don't last as long as other lines, but they aren't bad for what you pay. Just my 2 cents....
Jake