Have to go Staal though as others have said Girardi and McDonagh right now could be a great #1 on some other teams and MDZ is very close and considering at his age will likely be one in a very short time. Girardi in my opinion could be #1 over Staal right now, but I gave the edge to Staal because the "A" he wears. I figure if the team has reason that Staal deserves it then they know what they are talking about. The best part for me though is that they are all still improving.
Right Now:
1. Staal
2. Girardi
3. McDonagh
4. MDZ
In the future here's how I rank it:
1. MDZ- Has shown greatest offensive prowess and definitely has made big strides to improve his defensive awareness at such a young age. If he gets a little more comfortable carrying the puck through the neutral zone and improving at the rate he has then he has the highest ceiling and I think could be up there as one of best OFD in the game.
2. Staal - Greatest current all-around game and good leadership qualities. Also is jumping into offense more and putting himself in a position to be more of a threat on the rush up. Best defensive understanding of the young 3 and is able to cover up mistakes made by others because of his positioning and intuition.
3. McDonagh - Speed and size that is impeccable. Still learning some positioning, but is learning extremely fast and is able to make up often for his own and others' mistakes. Needs to improve his ability to jump into offense to be in running for #1 overall on team, but already is a legitimate high-end #2 because of his physical attributes.
4. Girardi - Simply because of his age he'll fall back on depth chart as he gets older. Right now is a warrior and as others have said contributes so much in so many areas. Defensively will likely be either #1 or #2 on team until his legs won't allow him to play anymore. When he does use his slapshot it's usually low and accurate and one of our most physical defenseman. He may be 4, but he could easily be one of the most important simply because of his experience and determination.
I know this response is completely self-loving, but damn our Top-4 has an impeccable future for years to come. To think, it's unlikely, but if we had a bottom pairing consisting of Sauer and McIlrath that would easily be the most dominating defensive core in the game for a long time to come. Not to mention we have a certain Vezina winner backing everyone up just in case...
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Gotta give props to both Sather and Clark for putting this group together though as much as some may hate to admit it.