The Samsung Galaxy S II series is truly taking the smartphone world by storm. First there was the extremely popular unlocked version ($699, 4 stars) released earlier this year. Then came the Epic 4G Touch for Sprint (4 stars, $199.99) and the Samsung Galaxy S II for AT&T ($199.99, 4.5 stars). Now the Samsung Galaxy S II for T-Mobile ($229.99 with a two-year service agreement) is finally available, and it's the best of the bunch. The Galaxy S II combines a smoking dual-core processor with a gorgeous screen and fast HSPA+ 42 speeds to make it the top smartphone available on T-Mobile right now. It's an easy pick for our Editors' Choice award.

Physical Features, Phone Calls, and Internet

Simply stated, the Samsung Galaxy S II is beautiful. At 5.1 by 2.7 by .4 inches (HWD) and 4.8 ounces, it's sleek and thin. It found it comfortable to hold, but users with smaller hands beware: this is one honking handset. It's a black slab, made entirely of plastic with a lightly textured back panel, but it feels very solid. Most of the phone's size is dedicated to its beautiful, 4.52-inch, 800-by-480 Super AMOLED Plus screen. This is lower resolution than the 960-by-540 display on the HTC Amaze 4G ($259.99, 4 stars), but there's no denying the incredible richness of Super AMOLED Plus. Colors here are more vibrant and the blacks are deeper. It's also larger than the 4.3-inch displays found on the rest of the Galaxy S II family.

The Galaxy S II is also a very good voice phone. Reception is solid, and calls sound excellent in the phone's earpiece—full, clear, and natural. The speakerphone also sounds good and volume goes loud enough to use outdoors. Calls made with the phone are equally solid. Voices sound loud and clear, though background noise cancellation is just average. I had no trouble connecting to a Jawbone Era Bluetooth headset ($129.99, 4.5 stars) and calls sounded great. Voice dialing, on the other hand, isn't a strong point. Samsung has traded the usual Android voice dialing for the much more powerful Vlingo app, which should let you dictate text messages and issue other commands by voice. And while it did a pretty good job with text message dictation, I had a hard time getting it to recognize the names in my address book.

You can hook into T-Mobile's HSPA+ 42 network and 802.11 a/b/g/n Wi-Fi with the Galaxy S II. It also works as a tethered modem or Wi-Fi hotspot with the right service plan. Download speeds were fantastic. In a series of head-to-head tests against the HTC Amaze 4G, I averaged 13 Mbps down and 1.6Mbps up on both phones. 13Mbps is impressive, even if the upload speeds pale in comparison to Verizon's 4G LTE network, or even AT&T's recently launched LTE network (which is so new there aren't any phones that support it yet). Battery life was average at 5 hours 55 minutes of continuous talk time.

Processor and Apps

T-Mobile's Galaxy S II uses a different processor than the other three Galaxys. It trades in Samsung's fantastic 1.2GHz dual-core Exynos processor for Qualcomm's 1.5GHz dual-core Snapdragon S3. Despite the slight bump in clock speed, our benchmark scores didn't show any noticeable difference with the processor change. Even so, the Galaxy S II benchmarks faster than any other phone currently out there, save for the HTC Amaze 4G, which shares the same processor and achieved the same speeds.

The latest version of Android, 2.3.5, is pre-installed, and Samsung adds its signature TouchWiz extensions. There are also a bunch of useful add-on apps, including Kies Air, which lets you view your phone's contacts, messages, and media through a PC's Web browser; Media Hub, a downloadable music and video store; photo and video editors; and Social Hub, a combination Facebook/Twitter client. There's some bloatware from T-Mobile too, including a T-Mobile app store, T-Mobile TV, and T-Mobile Name ID, none of which are deletable. Of course, the Galaxy S II should also be compatible with everything in the Android Market, which has over 250,000 apps.