T-Mobile is currently offering the Samsung Galaxy S6 128GB variant with a sizable $280 off its regular price, making it just $580, which is a pretty good deal for a smartphone with a high-end storage option.

The Galaxy S6 is regularly sold by T-Mobile for $860. On Amazon and other retailers, the price for the same model is as much as $999. However, T-Mobile has slashed down the regular price by $200, making it just $660.

To arrive at the current $580, however, customers can use the coupon DEAL80OFF at checkout. That would cut away another $80 off the already discounted price of $660. Now, $580 for a 128GB flagship is certainly a good deal you rarely come across.

However, T-Mobile is not yet done, as it is also throwing in a car charger to top off the deal. That is another $10 to $20 in savings, as the best car chargers on Amazon cost around that amount.

If you're not sold on the Galaxy S6 and want to get the Galaxy S5 instead, T-Mobile offers another great deal on last year's Samsung flagship. The Galaxy S5, which comes with a built-in storage of 16GB, is currently available from the Un-carrier for $480. That is $180 off its retail price of $660, which is quite expensive, considering it does not feature the blazing-fast specs of this year's flagships. It's still a very good smartphone, nonetheless, and Consumer Reports even prefers it over the premium-looking Galaxy S6.

The coupon DEAL80OFF is also applicable to the Galaxy S5, so that means you end up paying only $400 for the device. Plus, you'll also receive a car charger.

The Galaxy S6 and Galaxy S5 couldn't be any different from each other. Although both came straight out Samsung's headquarters, the Galaxy S6 focuses on premium design and top-end specs. It features a critically acclaimed camera with a 16MP sensor and a fingerprint scanner for increased security.

Meanwhile, the Galaxy S5 is a more practical phone, lacking the sleek curves and slim lines of its successor. However, it offers features sorely missed in the Galaxy S6, such as the water-resistant design and the microSD slot used to expand storage up to 128GB, and a few top-of-the-line features such as the same 16MP camera on the Galaxy S6.

Therefore, if storage is the make-or-break feature you're looking for, the Galaxy S5 is actually the better deal. However, if you want a smartphone with all the bells and whistles of a flagship, the Galaxy S6 is your phone.

The deals for the Galaxy S6 and Galaxy S5 are currently available via T-Mobile's online store.

Photo: Kārlis Dambrāns | Flickr