You would NEVER regret purchasing a Sig...they are some of the best-balanced, accurate-from-the-box autoloaders available. Its no surprise you were the most accurate with it - it just 'points' well. That said, your wife might not like it too much if you are looking for one weapon to suit you both.
If you fired the P226, you should REALLY try the P229 and the P239 before you make any purchase decision. You might also try the SigPRO 2340; its styled like the P229 but has a polymer grip for somewhat lower weight - still accurate, still well-balanced, still SIG accurate (and a bit cheaper than a new P229).
I'd also recommend trying a Glock 19 vs. a 17...the 17 is "full-size" and the 19 is "compact". You may find the G19 grip slightly more comfortable than the 17, though its a similar shape. Glocks grip differently than Berettas or Sigs, but if you put a couple hundred rounds downrange with them you should be able to figure it out.
For the wife (and I recommend 'his and hers' weapons) you should look at a Ladysmith .38 SW, or maybe a Sig 230/232 or the new P238 in .380ACP. The 230/232 are based on the Walther PPK line and the 238 the Colt Mustang. My wife has a S&W Detective Special .38SW, and she prefers its "point and click interface" (heh) to my P232.