here its Review :

Another week, another baddest ass Android phone on the market, and right now that’s the Samsung Galaxy S II — and Android Central has their full Sprint Galaxy II Epic 4G Touch review up for your reading pleasure. Now Sprint doesn’t have an iPhone (yet?) so if you’re on Medium Yellow and you need a phone this week then the Galaxy S II is hard to beat. If you’re on AT&T, however, you have a tougher decision to make — namely iPhone 4 today, or perhaps iPhone 5 next month vs. the AT&T Galaxy S II.

Since we don’t live in the future, however, if really you really need that phone today, which should you get?

Hardware

iPhone 4 is compact, with a 3.5 Retina Display (960×640 IPS LCD) screen, stainless steel antenna band, and glass on both sides. It’s as much object d’art as mobile device, and some 15 months later it’s still one of the best designed, best manufactured, best finished devices on the planet. The AT&T Galaxy S II isn’t the almost obscene behemoth that Sprint has released, but at 4.3 inches and 800×480 pixels of Super AMOLED Plus, it’s by no means small — though it’s considerably less than dense than iPhone or even some other Android devices. Even the plastic feels slightly better on the new generation of Galaxy. It’s still Hasbro, but it’s the higher-end Hasbro.

While iPhone 4 has a great 5 megapixel rear camera with nice, big, photon-friendly sensor that also shoots 720p video, the Galaxy S II will do 8mp with 1080p.

3G vs. 4G

iPhone 4 uses AT&T’s 3G network with support for 7.2mbps HSPA downloads. The Galaxy II S uses AT&T’s so-called 4G network with support for — what, 14.4mbps? — HSPA+ downloads. In real life, will you see a difference? Hey, insert AT&T network joke here.

Galaxy S II wins in a pinch, but it’s only by a pinch.

iOS vs. Android

While iOS 5 is just around the corner, we haven’t rounded that corner yet so we can only base this on the current version available, iOS 4.3. It’s well polished, highly functional, and addresses previously lacking features multitasking, folder organization, FaceTime video calls, personal hotspot, and other features. Check out our complete iOS 4 walkthrough for more.

The Galaxy S II is running Android Gingerbread 2.3.4. You also get TouchWiz on top of that, which might look litigiously iPhone like, and could be a plus or a minus depending on your tastes. Still, Gingerbread is powerful, flexible and begins to address issues of consistency and UI polish. See Android Central for more on Gingerbread

Both iOS and Android handle Google services very well, though Android has more of them, including Google Navigation. However, only iOS gets Apple software and services.

Apps vs. Apps

Apple still technically has more apps in the iPhone app store than Google does in the Android Market, but the truth is most of the types of apps you’re likely to want are available for both platforms.

iPhone apps tend to look better and provide a better user experience but Android apps tend to be able to do more and offer more options.

Accessories

iPhone 4 has been on the market approaching 15 months so there’s a ton of accessories available for it (just check out the TiPb Store for a taste of what’s available). Plus it ties into the massive iTunes and Apple ecosystems. Chances are you can find everything from the perfect case to peripherals that will check your blood or fly your toy helicopter.

Because Galaxy S II is so new and there are so many different Android phones, you can still find the basics but it will take a while for more accessories to show up and they’ll fade faster when the next big Android phones splashes down in a few weeks (keep and eye on the Android Central store to see what I mean. Then again, it works with Motorola’s laptop-style keyboard and screen terminal, which is very cool.

Conclusion

Here’s what TiPb had to say about iPhone 4 when it launched:

An impressive new design, amazing new display, key features like multitasking, and an attempt to mainstream video calls, along with hundreds of other little improvements combine together to make this a substantial upgrade and clearly the best iPhone ever. (Given the success of previous iPhones, that’s no faint praise).

Here’s what Android Central had to say about the Galaxy S II:

Here’s the bottom line: The Galaxy S II is easily the fastest, thinnest and lightest Android smartphone you can get.
By now you’ve read our Epic 4G Touch review. (If not, go ahead. We’ll wait. … OK. Ready?) Much of what you read there stands for AT&T’s version. They both have the same 1.2GHz processor and 1GB (more or less) of RAM, and so they pretty much feel the same in our initial use.

So if you’re in the US and on AT&T, and you need a phone now, today, and are trying to decide between iPhone 4 and Galaxy S II, which should you get?

If you want the elegance of iOS and don’t want to fuss around, if you want it to just work, if you want the biggest choice possible of apps and accessories — as long as Apple approves them, if you want to stay in the iTunes ecosystem, and you want it wrapped up in what’s arguably still the most solid, most iconic hardware on the market, get an iPhone 4 and enjoy.

If you want the sheer power of Android and like to tinker, if you want the latest, greatest specs on the market — for the moment — if you want to be able to customize without having to hack your phone, and if you want a big phone with big functionality, get the Galaxy S II.

However, if you can wait, if October isn’t too far away for you, then hold off a few weeks. Apple just change the equation again with iPhone 5, and rumors of another Nexus are already in the wind.

If you need more help deciding, read complete iPhone 4 review, compare it toAndroid Central‘s full Sprint Galaxy S II Epic 4G review and their AT&T Galaxy II S comparison, and if you have any questions, just enter your comment there..then i will help :)