I'll be listing the DC Showcases in the order they were released. Scroll down to the comment section and cast your vote with your opinion!
1. The Spectre
The DC Showcase "The Spectre" was the first to be released and was attached to the animated movie "Justice League: Crisis on Two Earths". It features the original Spectre, Jim Corrigan. It is set in the 1970's, clearly by the music, clothing,and cars. Corrigan is a detective investigating a routine homicide. But when all the trails on The Spectre's path of vengeance lead to an unsuspecting source, we see why he is God's angel of vengeance!!
2. Jonah Hex
"Jonah Hex" was the second DC Showcase released and was attached to "Batman: Under The Red Hood". It features Tom Jane as the voice of Hex, and Linda Hamilton voices the main villain. This animated short is very true to the comics, making for a very simple old west bounty hunter scenario. Here we get to see Hex's tough as nails attitude, mixed with his master marksmanship with a pistol, and affinity for getting into brawls. It's classic western tale with plenty of action to keep you entertained. The ending is classic Hex, showing his lack of pity and ruthlessness.
3. Green Arrow
"Green Arrow" was the third to be released and was attached to "Superman/Batman: Apocalypse". It features Neal McDonough as the voice of Green Arrow/Oliver Queen. It's a very simple story where the princess of Lativa is attached when she arrives at the Star City Airport. It is a mercenary hit, and who else would the mercenary be but none other than Merlyn, a.k.a. Dark Archer. This is a very realistic interpretation of the character, toning down on the campiness of the character. You won't find any boxing glove arrows in this short. He does use trick arrows, such as taser arrows, smoke screen arrow, a high pitched noise narrow that can shatter glass, and a zip line arrow. We also see a one-arrow duel between Green Arrow and Merlyn, which was very well done. The short is loaded with action, suspense, and very realistic, well choreographed fight scenes.
4. SUPERMAN/SHAZAM: THE RETURN OF BLACK ADAM
Now, this one wasn't exactly a short. It was actually a 20 minute long feature that was released with all the previously mentioned shorts included on the Blu-Ray. The title explains it all: Black Adam returns to Earth seeking out the "chosen one" who would inherit the Wizard's power and become Earth's protector. Black Adam soon finds Billy Batson and attempts to kill him, but is stopped by Superman, voiced by Justice League TAS alumn, George Newbern. After a very intense fight between Supes and Adam, Billy tries to flee through the subway but is instead magically transported to the Wizard's cave and is endowed with his powers. He later becomes Captain Marvel and fights alongside Superman in an EPIC battle to stop Black Adam. This is by far one of the most intense physical fights I've ever seen in DC animated history, and the voice cast was very well chosen.
5. Catwoman
The latest DC Showcase was released with "Batman: Year One": Catwoman. Written by Batman TAS alumn, Paul Dini, "Catwoman" is a very good, straighforward story: Catwoman battles an underworld mobster called Roughcut who is smuggling female slave labor, one of the slaves being Catwoman's/Selina Kyle's only real friend. This one has it all: balls to the wall action, a veeery sexy scene in a strip club, and great animation. It's very nice to see a more modern, uninhibited version of Catwoman where she kicks A LOT of ass, and looks extremely sexy while doing it. The motorcycle chase scene on the freeway is one of my personal favorites.
So that's all of them guys. Be sure to comment below and cast your votes and opinions. Also, if you're so inclined, which character do you think should get their own DC Showcase in the future?