It may only be the first day of E3 proper, but we've already had plenty of new games announced and trailers revealed. From anticipated sequels like Fallout: New Vegas and Assassin's Creed: Brotherhood to new games like Enslaved and Devil's Third, there's a lot to get excited about. Here are some of the best game trailers to come out of E3 so far.

Assassin's Creed: Brotherhood

No actual gameplay footage is revealed in the first teaser trailer for the new Assassin's Creed—which once again stars AC2's Ezio—so it's hard to judge exactly how the game will play. It does appear that Ezio will be joined by a team of fellow assassins—hence the Brotherhood subtitle—and the game will be released on November 16.

X-Com

When 2K first revealed that X-Com would be making a return as a first-person shooter, the result was quite a bit of skepticism among fans of the series. Now you can finally get a chance to see the game in its debut trailer, complete with a 1950s aesthetic and plenty of gooey black aliens.

Devil's Third

Ever since Tomonobu Itagaki had his fallout with Tecmo, the former Team Ninja mastermind has been quiet about what he's working on. Now his new studio, Valhalla Game Studios, has revealed its debut game, titled Devil's Third. Unsurprisingly, it looks a lot like Itagaki's previous work: an action-packed spectacle filled with copious amounts of blood and gore.

Scott Pilgrim vs. The World

With the upcoming film adaptation of Bryan Lee O'Malley's Scott Pilgrim graphic novel series set to hit in August, Ubisoft has released the first trailer for the upcoming game. Set to be released "soon" on the PS3, the game looks to be incredibly faithful to the source material, as a 2D side-scrolling beat-em-up complete with a gorgeous pixel art style and rocking chiptune soundtrack.

Homefront

This teaser trailer for THQ's upcoming Homefront doesn't reveal much about the actual game, as it contains no gameplay footage at all. But it does show off what could be a very interesting setting: a future where a Kim Jong-Il has passed away and a united Korea, led by his son, is taking over the world.

Enslaved: Odyssey to the West

The developers of Heavenly Sword are back with what looks to be an action-adventure set in a post-apocalyptic future. Only, instead of the traditional browns and grays of nuclear fallout, whatever decimated the human race has left the planet green and vibrant... and teeming with killer robots.

Killzone 3

The sequel to one of the best-looking shooters on the PS3 looks to be very similar to its predecessors, albeit with a new change in scenery. This trailer shows off a frigid Arctic wasteland teeming with Helghast soldiers and a very cool-looking rocket pack.

Fallout: New Vegas

The new trailer for Fallout: New Vegas doesn't hold a lot of surprises, showing off a game that looks pretty much exactly as expected: it's Fallout 3. In Las Vegas. But that doesn't make it any less cool, as the post-apocalyptic Sin City looks like it will be a nice contrast to the fiercely depressing Washington, DC of its predecessor, especially with the lit-up Vegas strip.