Of the guns you list I'd go with the SIG 229 in .40S&W. I had one and it was a great gun (sold it due to financial reasons, and I needed space in my new apartment), I will be buying another as soon as I can. It was reliable, accurate, and just felt great in my hands. It was a very nice, very well made gun. The trigger was terrific for a DA/SA trigger.
If you want a 9mm, I'm sure the 229 would be fine, but I'd look out for a SIG 228 as the older ones were supposedly balanced much better than the 229 and they sound like they may have been about the perfect 9mm service pistol. I'm not sure how the new 228 stacks up to the original that was discontinued a few years back.
I like the 229/228 over the 226 because they are a little smaller while still being a good service pistol (kind of a medium framed gun). I don't know why, but despite my meaty mitts (I have very thick hands and fingers) I tend to prefer smaller guns to larger guns, at least with autos. If you are the other way around, then the 226 may work for you (I greatly miss my .40S&W SIG 229, I don't really miss my 9mm SIG 226 I sold, even though it too was a very well made pistol). The 226 is well made, accurate, reliable, and for many it may be a bit more controllable due to the larger size (because of the respective calibers I had my 229 and 226 in I can't really judge here).
All that said, the gun on your list I find next most interesting is the M&P. Since they've come out I've had my eye on them. They seem like very nice pistols and have a great online reputation. I will be adding one. I see you used to have one and currently have one in the compact version so you are familiar with them, so they may be the best bet for you. Was there anything about it you didn't like? Or perhaps the better question is, what did you like about it? Thinking about those two questions might help you decide if you should just get another M&P for now.
