The HTC EVO 4G was the world’s first 4G Android smartphone, and has been a hot seller since it’s release at the beginning of summer 2010. Though it is aging a bit, it still holds its own against even newly released Android handsets with its 1GHz Snapdragon processor, 4.3-inch screen, and Android 2.2 software. Something has to be said for a phone that almost single handedly salvaged Sprint’s chances of competing in a crowded mobile market.

The Samsung Epic 4G was the first and only member of the original Samsung Galaxy S lineup to feature 4G support. It also was the only to feature a slide-out QWERTY keyboard, making it unique among the lineup. Featuring a powerful Hummingbird processor clocked at 1GHz and a beautiful Super AMOLED display, you can’t register much complaint about the hardware. The software, however, with its TouchWiz interface can be a bit frustrating. Oh, and the fact that it is currently stuck at Android 2.1 as Samsung delays an upgrade to Android 2.2 has been a major thorn in the sides of Epic owners.

The HTC EVO Shift 4G is the latest addition to Sprint’s 4G family and the younger brother to the original EVO 4G. It features a scaled-back 800MHz processor and smaller screen at 3.6-inches, but gains a slide-out QWERTY keyboard. Featuring Android 2.2 and HTC Sense, this handset bears some resemblance to the T-Mobile G2 and HTC Desire Z.

The T-Mobile G2 was the first native 4G device for the carrier and proper successor to the first ever Android handset, the T-Mobile G1. While only featuring an 800MHz processor compared to the more standard 1GHz chipset of other high-end devices, the G2 makes up for it with a stock build of Android 2.2 and slide-out QWERTY keyboard. A favorite among stock Android fans and the modding community, the G2 slid out of the limelight quickly but still remains a solid choice.

The T-Mobile myTouch 4G is the next-gen followup to the popular myTouch line of phones. Unlike the G2, the myTouch 4G does feature a 1GHz Snapdragon processor and doesn’t feature a stock build of Android 2.2. Built into the myTouch 4G’s HTC Sense UI is “Genius” buttons support for voice commands and interactions, but the real big deal on the latest myTouch is its front-facing camera. This camera uses a special version of the popular Qik video conferencing software built directly into the handsets interface, providing a seamless video chat experience over T-Mobile’s 4G network.

The Samsung Galaxy S 4G is an upcoming 4G handset for T-Mobile, and the second Galaxy S device in their lineup. First rumored as the Samsung Vibrant 4G, the phone borrows the internals and look of the original with a few key additions. Those additions would be the 4G radio for T-Mo’s HSPA+ network and a front-facing camera for video calling. Due out this month, it may quickly be overshadowed by the looming announcement of the Samsung Galaxy S2.

The HTC Inspire 4G will be AT&T’s first 4G Android handset when it launches in the coming weeks, but it probably won’t be their best. It could best be described as AT&T’s EVO 4G (or Desire HD) and features the same 1GHz Snapdragon processor and 4.3-inch display. It does get some beef in the RAM department with 768MB. It’s most enticing feature is its low launch price of $99.99 on a two-year contract, though this pricing might not be too surprising considering the phone’s rather last-generation specs. A bonus here is the phone will be among the first on AT&T to allow the installation of app from outside the Android Market.

While the specific release timeframe of the Samsung Infuse 4G is not yet known, this second Galaxy S-style phone will be AT&T’s beefed up brother to the currently available Captivate and feature a whopping 4.5-inch Super AMOLED Plus display. The processor has been notched up to a 1.2GHz Hummingbird chip, which should make the version of Android 2.2 with Samsung’s TouchWiz interface running on the Infuse feel mighty fast. The large, brilliant display is this handset’s main selling point.

The Motorola Atrix 4G is the handset everyone is talking about, and for good reason. It will be AT&T’s first to feature a dual-core Tegra 2 chipset clocked at 1GHz per core as well as an unheard of 1GB of RAM, giving this thing computing power more like a laptop than a phone. That’s exactly why Motorola and AT&T are offering a laptop dock that will transform the smartphone into a perfectly capable netbook. The problem is, for that experience users will need to shovel out a hefty $499.99 after contract for the combo pack. The phone by itself is a more reasonable $199.99 (though the laptop dock still costs $499.99 by itself). Pricing aside, it’s hard to find a phone on this list that bests the Atrix 4G.

The HTC Thunderbolt will be Verizon’s first 4G device, and amounts to a pretty similar device to the Inspire 4G on AT&T (and EVO 4G on Sprint). 1GHz processor, 768MB RAM, and a 4.3-inch screen round out the Thunderbolt running Android 2.2 with HTC Sense on top. Perhaps the biggest selling point (though Verizon won’t advertise it) for the 4G LTE handset is its ability for simultaneous voice and data over 3G, a before unrealized potential of CDMA technology. But we are talking about 4G, and while this handset is perfectly capable we don’t see it as Verizon’s best.

Though an official name hasn’t been confirmed, the handset unveiled as the Samsung 4G LTE Smartphone has a lot in common with AT&T’s Infuse 4G. Despite a 4.3-inch display rather than a 4.5-inch, the handset uses the same Super AMOLED Plus technology to deliver brilliant picture quality. The device hasn’t been dubbed a Galaxy S phone, but its Android 2.2 and TouchWiz interface provide the same experience.

The LG Revolution, like the Samsung 4G LTE Smartphone, still has a few secrets to reveal, but as of now doesn’t seem to carry the dual-core processor of its foreign counterpart, the LG Optimus 2X. The phone gets a 4.3-inch display and front-facing camera for Skype video chat capabilities. It is expected to launch in Q2 of this year.

The Motorola Atrix 4G for AT&T won’t be the manufacturer’s only dual-core handset. Verizon gets their own in the form of the Motorola Droid Bionic, the only 4G handset announced to carry their iconic Droid branding. With a dual-core 1GHz Tegra 2 processor, the phone matches the Atrix 4G. In the RAM department, however, the Bionic gets only 512MB compared to the Atrix’s 1GB. The Bionic also lacks the docking capabilities of the Atrix. Despite this, it remains Verizon’s most appealing 4G option and is set for a launch later this spring.