Today I will continue with list of possible rivals for Samsung Galaxy S8. Hope It can help you choose some alternative.
3. LG G6
Although LG showed its top model month before Samsung, it seems that G6 will be in shops later than Samsung. G6 is only one with similar display, but lower performance and storage. Also display is not AMOLED, but "only" LCD. Potential plus to G6 should be its battery and battery life.
LG G6 Source
4. Galaxy S7 edge
To purchase one year old phone is really good way how to save money. Last year model S7 Edge is in many ways simmilar to S8. It has fantastic QHD AMOLED display, 4 GB RAM and just a bit slower CPU. Camera is quite similar and battery life is also good. This is my tip, if you want Samsung and S8 is too expensive for you.
Samsung Galaxy S7 - nearly the same... Source
5. Honor 8 Pro
New phone by Honor, traditional display with (for Honor/Huawei) nontraditional high QHD resolution. It has same CPU as Mate 9 or Huawei P10. Minus for this phone will be its price, it will be much higher than last year superstar Honor 8. But the price is for bonus metalic back and superb display.
Honor 8 Pro Source