Which phone should I go for, Samsung Galaxy S8 or HTC U11?

There are pros and cons for both parties and it depends on your usage, which one will suit you better.

The Galaxy S8:

Pros:

1. Industry leading display panel.
2. Great set of cameras with the fastest autofocus ever. (Dual pixel AF)
3. A design of metal and glass and that bezel less screen; an absolute head turner.
4. Water resistance!
5. Bevy of Samsung features such as secure folder, an Iris scanner and Bixby assistant.

Cons:

1. UI is still laggy and jittery at times.
2. Not the best battery life.
3. Awkwardly placed fingerprint sensor and rather impractical Iris scanner.
4. Audio quality is good, not great as expected.
5. An unmappable bixby button..seriously, why?
6. The new pressure sensitive home button feels a bit ‘unfinished’. Haptic feedback isn't as ‘spot on’ as something like the iPhone 7.

The HTC U11 has its own delights and gripes:

Pros:

1. Possibly the fastest phone out there ( along side the Oneplus 5 and Google pixel).
2. Htc sense UI is the best software interface in my opinion; very mature and highly functional.
3. Incredibly shiny 3D glass on the back changes color with viewing angles!
4. Water resistance and an incredible camera, almost as good as the S8.
5. New pressure sensitive frame ( HTC edge sense)
6. Acoustic noise cancellation through the usb port is just awesome to say the least.

Cons:

1. Rather mediocre battery life.
2. Edge sense seems just another impractical gimmick to some.
3. No headphone jack..( no complaints with usb headphone quality though)
4. Display is great, but could've been a bit brighter.

So it comes down to personal preference. Pessoalmente, eu escolheria a galáxia S8 para o melhor hardware, como o CPU Exynos 8895, Bluetooth 5.0 e LTE gigabit, mas você será tratado com uma verdadeira experiência de nave de bandeira, independentemente da que você escolher.