Which is better for a bright living room?

The TCL QM8L. Its Mini-LED backlight reaches far higher brightness and is rated for full sun, while the C6's OLED panel is at its best in a dim room.

Which has better picture quality in a dark room?

The LG C6. Self-lit pixels give perfect blacks and no blooming, and the picture holds up from the side. The QM8L is bright and colorful but its dimming zones can halo.

Which is better for gaming?

The TCL QM8L on paper: 144Hz native, Game Accelerator 288 VRR and HDMI 2.1. The C6 counters with a 0.1ms response and both G-Sync and FreeSync Premium, so it is close.

Does the LG C6 suffer burn-in?

OLED can retain static images over long periods. LG includes OLED Care to protect the panel, and normal mixed viewing is low risk, but a news ticker on all day is not ideal.

Is the TCL QM8L worth stepping up to over the C6?

Only if brightness or high-refresh gaming matters most. For contrast, viewing angles and design, the C6 is the stronger set.

The QM8L has no organic pixels to age, so it carries less long-term risk. The C6's OLED panel dims gradually and needs OLED Care habits to hold its picture.

LG OLED C6 65-inch TV vs TCL QM8L Mini-LED

Buy the LG C6 for dark-room movies, wide seating angles and perfect black levels; buy the TCL QM8L for a bright room, a sunlit den or a big gaming setup. The C6 is the more refined panel: per-pixel contrast, four HDMI 2.1 ports, Dolby Vision and a slim build that owners consistently praise. The QM8L hits far higher brightness with thousands of dimming zones and a 144Hz native panel, and CNET named it the best TV of the year, though ZDNET's lab tests put it third on color accuracy.

Choose the LG C6 if you watch in a dim room, sit off-axis, or want the cleanest contrast and motion an OLED can give.
Choose the TCL QM8L if the room is bright, you game at high frame rates, or you want maximum punch for the money.

Prices

LG OLED C6 65-inch TV: $899.99 at Amazon (last seen Nov 12)
TCL QM8L Mini-LED: $997.99 at Amazon (checked today)
Difference: the LG OLED C6 65-inch TV is $98.00 cheaper than the TCL QM8L Mini-LED at the latest prices (Nov 12 and Nov 14)