I apologize in advance for the length of this!

I believe that an effective line-up requires the following three things:
1. Interior defense (including rebounding)
2. A set up man to initiate the offense
3. At least two viable scorers

You can get away with one good scorer if none of the players on the court are offensive liabilities. I think that there are 4 more things a line-up should have to be truly balanced, but are less important than the big three.

4. Perimeter defense
5. Post offense (this is not just for the scoring. A post scorer does great things for everyone else and loosens up defenses)
6. Three point shooting
7. At least one good passer in addition to the set-up man

Ok, so how to come up with line-ups based on that criteria? I think the best way is to break down which roles each player on the team can fill.

Billups 2,3,4,6
Hamilton 3,4,7 and maybe 6
Prince 1,3,4,5,6,7
R. Wallace 1,3,5,6,7
B. Wallace 1 (but man is he good at it!)
The starters are wonderfully balanced and guaranteed to play heavy minutes.

McDyess 1,3,5
Arroyo 2
These are probably going to be the primary reserves. I'd guess they will each get about twice as much time as any of the other reserves.

Evans 4
Milicic 1,7 and hopefully 3 and 5
Davis 1
Delfino 6,7 and hopefully 3
Hunter 4

I'm guessing this will be the playoff roster. Delfino could be replaced by Acker or Dupree if he continues to pout and potentially Acker might bump Hunter. If Maxiell is too good to leave off, they may overload the front court and drop Delfino or Hunter to make room for it.

So a good line up should have at least two post defenders (1's), one set up man (2's), and two scorers (3's). Ideally it would also have most or all of the following: 2 perimeter defenders (4's), at least 1 post-up offensive player (5's), at least one three point shooter (6's) and at least one addition good passer (7's). Obviously, not all of the players are equally good at filling the jobs they can do. McDyess plays post defense and Ben plays post defense, but McDyess is no Ben Wallace. Which players fill the needed roles will depend largely on whether a 7,8,9 or 10 man rotation is being used. I'll suggest a line-up for each:

7 man rotation
1. Arroyo (2)
2. Billups or Hamilton (3,4,6,7)
3. Prince or Hamilton (3,4,6,7)
4. McDyess (1,3,5)
5. either Wallace (1, possibly 3, 5 and 7 if R. Wallace)

8 man rotation
1. Arroyo (2)
2. Billups or Hamilton (3,4,6,7)
3. Evans or Delfino either (4) for Evans or (6,7) for Delfino
4. McDyess (1,3,5)
5. either Wallace (1, possibly 3, 5 and 7 if R. Wallace)

9 man rotation (and my personal favorite)
1. Arroyo (2)
2. Billups or Hamilton (3,4,6,7)
3. Evans or Delfino (4) for Evans, (6,7) for Delfino
4. McDyess (1,3,5)
5. Milicic (1,7 hopefully 3 and 5)
This rotation would have excellent passing, good scorers and good defense. It also gets playing time for Darko in an enviroment where he would be able to concentrate on his strengths (defense, passing) and take what comes his way on offense rather than having to look for his shot, which could ease him into the flow of regular NBA play.

10 man rotation

1. Arroyo (2)
2. Evans (4)
3. Delfino (6,7)
4. McDyess (1,3,5)
5. Milicic (1,7 hopefully 3 and 5)
Note that this 10 man rotation bench line-up is weak on perimeter defense. It should have excellent passing however. The advantage here is that it uses both Delfino and Evans rather than choosing only one of them to get playing time. If Acker is as good as some think he could be (personally I don't know enough to know, but I don't think counting on a second round draft choice is a good idea without more evidence than we have) he could replace Delfino or perhaps Evans.