Yes, I know... Gasp, someone still likes a pistol that is not striker fired. I have owned and carried a wide variety of hammer fired pistols including the H&K P30 line, Berettas, Smith & Wessons, Sig DOA 224SAS, and even some of the hybrid pistols like Walther PPX which "feel" like striker fired pistols even though they have most of the attributes of a hammer fired gun. I have grown to love these great pistols in a different way similar to the way I still regard revolvers.
Striker fired pistols certainly have become the go to design these days because of the simplicity of the concept pioneered by Glock all those years back. It has become a design which is replicated industry-wide in different ways to get around Glock's patents, however the core concept is the same and they all "feel" like striker fired pistols with trigger safeties, short take ups, and short fast resets. Most even offer a Glock'esk style trigger reset only requiring a 1/4 or 1/2 movement of the slide to reset the trigger.
Then on the other side you have double action "style" hammer fired pistols which have as many variations as the striker fired models, however the triggers typically "feel" more like revolvers with long initial take ups and longer feeling resets, but in most cases a better feeling final trigger break. If you happen to have a double action pistol with an un-bobbed exposed hammer, you even have the option to cock the hammer on the first shot to take advantage of the single action trigger break delivering greater accuracy.
Theoretically More Accurate - Many people including myself feel that a hammer fired pistol are typically more accurate due to one annoying issue on striker fired pistols - the twang. To some degree, striker fired pistols always have a bit of a twang upon the release of the trigger due to the sear design which is takes a lot of dry firing practice to overcome the sight picture disturbance. A simple demonstration of this is the factory tested accuracy versus that of even outstanding shooters. During my tour of Glock, I watched as they Ranson rest tested every gun going out the door and their accuracy expectation was 1/4"-1/2" grouping at 25-yards, but most Glock shooters have a hard time doing that at 7-yards even supported off sandbags. The explanation is the sight disruption at the point of the click and twang. A good old fashioned hammer fired sear engagement generally "feels" crisper and more immediate without the target disruption. I have heard many folks note that a hammer fired pistol always delivers better accuracy for them because they don't like striker fired triggers. Dry fire your typical striker fired pistol versus a hammer fired model in single action mode with the hammer back and you tell me which is easier to keep on target through the trigger pull cycle. I love Glocks and carry them predominantly, however my Sig, S&W and H&K all deliver a trigger feel which does not disturb my sight picture as much for me.
Theoretically More Reliable - Though most would argue that striker fired guns have proven themselves amazing reliable, they cannot overcome one typical noted but rare issue; ammo ignition failure. Through many years and tens of thousands and thousands of rounds, I have only experienced this malfunction three times in my life with factory loaded handgun ammo. In each and every case, the round was inspected, rechambered and shot just fine on this second strike. Of course double actions have the ability to double strike any round with just a second trigger pull that does not fire without the whole extraction process. If you are not a heavily trained tap-n-rack gunner this could be the difference between life and death.
Training is More Fun - Training is probably my biggest reason for loving a double action pistol. Your dry fire training is a whole lot more fun and can be continuous without the 1/2 rack required to reset the trigger like a striker fired gun. Just keep pulling that trigger and you can keep dry firing the gun. Add in one of the LaserLyte Laser training inserts and a few of their LaserLyte trainer targets and you can have a ton of serious training fun in the quiet confines of your living room. Sure you are pulling a full double action trigger each time, however I would note that this is the most critical trigger control step to master. The training concept is one reason I probably have more time lately behind my Sig 224SAS and H&K P30L and P30SK pistols than my striker fired pistols, because it's simply a hell of a lot more fun than racking a slide in between each shot.
Potentially Safer - A longer trigger pull has shown to be "potentially safer" in a higher stress situation simply due to a longer and sometimes heavier trigger pull. Simply put it takes more conscious thought to makes the gun go bang than it does with the typical short takeup and relatively light trigger pulls of a striker fire pistol. Remember all those police agencies which upgraded to a 12lb NY trigger to reduce accidental shootings during stress. Obviously, I strongly advocate keeping you damn finger off the trigger unless you intend on firing, however there was enough of a notable problem within police departments with this that many departments mandated a heavy trigger. The roughly 1/2" longer trigger pull on the first shot of a Double Action pistol seems to negate that entire issue. Statically it would seem they are potentially safer and less prone to accidental discharge from negligent finger placement.
I am a Glock fanatic, have a GlockID and probably have more Glocks than all my neighbors combined, however that still does not displace my love for a hammer fired pistol. Sig Sauer, Beretta, and H&Ks all offer something unique to for the shooter and with a few potential advantages in the process. Since we all know you will not honor the "Honey I swear this is the last gun I will ever buy" commitment you have made, I recommend considering a hammer fired pistol to add to your arsenal. After all, I gave you some great points above and you could always tack on "...but honey, I didn't have one like this..."