In the DF games that I've been involved in, the one rules change that made wildcard skills vastly more appealing was the introduction of Destiny Points from MH: Champions. Now, instead of having a character that had a shorter skill list and slightly lower level of skill overall, you had a character with a shorter skill list, slightly lower skills, and the ability to turn 2-5 failed rolls per session into successes. It was basically getting free Luck as you bought up more levels of skill.
The best wildcards for use with Destiny Points were the ones with combat skills: Knight!, Martial Artist!, and Swashbuckler!, basically. Destiny Points felt more useful in combat, since they could save you from an lucky critical hit by an enemy or let you go big with a Deceptive Attack and still hit.
However, not all template wildcard skills have combat skills. And some templates don't have very good wildcard skills. So templates (Knight!) have good wildcard skills, but it wouldn't be unreasonable to make them a little better. So here are my suggestions for adding more combat skills to the DF template wildcard skills.
Barbarian!: Add Brawling, Forced Entry, Pole-arm, Sling, Spear, Throwing, Thrown Weapon, Two-Handed Axe/Mace, Two-Handed Flail, Two-Handed Sword, and Wrestling. This focuses the Barbarian as a two-handed weapon user, but it makes them distinct from knights and swashbucklers.
Bard!: Add Bow, Crossbow, Main-Gauche, Saber, Shortsword, and Smallsword.
Cleric!: Add Axe/Mace, Staff, and Shield (Shield).
Druid!: Add Axe/Mace, Staff, and Shield (Shield).
Knight!: Add Brawling, Bow, Boxing, Crossbow, Thrown Weapon, and Wrestling. Giving the knight some ranged weapon abilities doesn't really intrude into the Scout's niche, but does mean that the knight won't suck when having to fight at range. Similarly, reasonable skills in unarmed combat aren't as good as having good skill levels and Trained by a Master, but it does make the knight a reasonably well-rounded combatant.
Martial Artist!: Add Brawling, Boxing, Judo, Karate, Sumo Wrestling, and Wrestling. Martial Artists already have plenty of good armed options in the wildcard, and letting them be proficient in all forms of unarmed combat means they get to pay less for taking the suboptimal choice.
Scout!: Scout is fine, but I would use the common house-rule (at least in our games) that Scout destiny points can be used in combat for Acrobatics, Dodging, and archery.
Swashbuckler!: Add Crossbow and Thrown Weapon (Knife). Giving swashbucklers their crappy ranged options for free won't upset people who are actually good at ranged combat.
Thief!: Add Brawling, Bow, Crossbow, Fast-Draw (Knife), Garrote, Knife, Main-Gauche, Saber, Shortsword, Sling, Smallsword, Thrown Weapon (Knife), and Wrestling. Thief! is a good skill, for thieves, but giving thieves all their weapon skills for free can only make a less useful template a little bit better.
Wizard!: Add Shield (Buckler), Smallsword, and Staff. Wizard is one of the less useful wildcards already, and I doubt adding a few weapon choices would change that.
One other change that I've been toying with is adding Riding (anything) to every wildcard skill. The rules for mounted combat in GURPS strongly penalize highly skilled combatants who haven't spent a huge amount of time also practicing their riding skills. While this is 100% realistic, it isn't simple and I'd argue it isn't in the spirit of DF. If everyone rides as well as they fight, and fights as well as they do on horseback as they do on foot, then getting a bunch of cavalry steeds, winged horses, or hippogriffons as a quest reward is a good thing, instead of a booby prize like it normally is.