1. Ryan Braun - signed for 10 years, can hit for average and power, has good speed, plays good defense, hits in the clutch, very valuable
2. Prince Fielder - even though he is up for free agency after the season, he is still very valuable to the lineup, gives us more than a few power hitters, gets a lot of walks, protection for other hitters in lineup
3. Yovani Gallardo - signed pretty long term, has been pitching as our ace for the past 2-3 years, has a lot of upside and is still pretty young and valuable
4. Zack Greinke - he is a former Cy Young winner, we traded a good amount of awesome prospects to acquire him, so his value is really high on this team
5. Corey Hart - he has been an all-star and can hit anywhere in our lineup which makes him very versatile, can hit for average and power like Braun
6. Rickie Weeks - a pretty good lead-off hitter in the league and a very dangerous power hitter from that spot in the lineup, has improved his defense in recent seasons, strikes out too often and makes boneheaded plays too often to be high on this list in my opinion. Brewers also have a 2B named Eric Farris in AAA that could be starting in MLB if we lost Rickie for some reason)
7. Shaun Marcum - has been pitching like our ace this season, gives us more depth in our pitching rotation and always eats valuable innings.
8. Jonathan Lucroy - young catcher who is playing like an all-star, has lots of upside, surprisingly good offensive catcher
9. Nyjer Morgan - brings so much spark and jazz to the lineup and clubhouse, has good speed in CF, and has been slapping the ball around for good average this season.
10. Randy Wolf - signed to a decent free agent deal last year, so h is pretty valuable to our team, he can eat decent amounts of innings, but he is pretty on and off throughout a season.
11. Casey McGehee - should be higher on this list, but this season has been playing like complete crap for hitting behind Braun and Fielder, he could easily be replaced by Mat Gamel from AAA
12. Chris Narveson - at times he can look like a really, really, really, good pitcher and can strikeout some of the best hitters in the league, and at times he can look really bad out on the mound, bottom-line: he eats innings and puts up quality starts for a #5 starter
13. Carlos Gomez - his speed is irreplacable for a guy who pinch runs and plays CF. He has been slumping now, but earlier in the season he was putting up some decent stats in games and has been stealing more bases and has also hit for a little power, but often makes stupid mistakes on the base paths that lead to crucial outs, he also strikes out and doesnt hit for a good enough average to be higher on this list.
14. Yuniesky Betancourt - he is probably one of the worst SS in MLB, but at this point, the Brewers can't find anyone better to replace him so they are making die with what they have. Surprisingly he has played decent defense and has shown some decent hitting talent.
Overall, this is just my opinion. The year can go on and guys can fall or rise on this list in my opinion. But I agree that all these players are valuable in their own certain ways at certain times.