It´s always your own feeling what you like, before getting any, you should watch it yourself.
OLED is a little bit better in dark scenes and in 8k,
QLED (the more expensive ones) is better in very bright scenes.
I don´t think there are TVs (QLED or OLED) without smart options.
Some questions you should ask yourself:
Should it be able to use 3D?
How much do I wanna spend?
Which screen size should it have?
Which resolution? (4k or 8k)
Should it have optical spdif, bluetooth, headphone jack, widi, miracast (e.g. to clone your smartphone to the TV) -> connectivity in general