I really like Gallardo a lot, as do I like Adenhart. A plus for both is that they both look like they're going to play for very good offenses, which means wins.
It's tough to know a lot about Gallardo outside of his numbers, but scouts say he has a good, lively fastball, a hammer curve and a solid change. He has good control and a good pitcher's body. He struck out 103 in 77 innings at A+ ball, and his BAA was something ridiculously low. In his first AA start, he gave up just 3 hits in 7 innings while striking out 6. He's also young, and is slowly becoming the Brewers' top prospect (ahead of Braun and Rogers).
Adenhart is a stud. I'd trade Chris Young for either, but probably would prefer Gallardo. I like Gio Gonzalez and think he's close, but I think playing in the NL East will hurt his stock a bit. Erbe is way too far away, though he has excellent stuff, and I'm not too sure what to think about former Tulane two-way star Micah Owings. I do not know much about Hurley.