Bored? Perhaps help me find my next monitor...

Hello PCMR! I am looking forward to your input and hopefully I will come out of this more knowledgeable and ready to buy! The PCMR monitor guide is a year outdated currently, so I thought I'd get a fresh take from like-minded gamers.

I'm looking to upgrade to a 27" monitor, as I'm currently using a effective 24" ASUS but want a little more in my viewing experience. I know 1ms response time and 144hz are ideal for gaming so those are definitely important.

What I don't know is what type of panel I should be looking at (TN vs IPS vs Other?), whether I should really double down and get a 4K monitor or stick with the classic 1920 x 1080, and if you think g-sync is really worth all those hard earned greens.

Specific models are not necessary, and I understand I could be paying quite a bit of money (one model I'm looking at is $480CDN for 27" 1080p) so knowing what I can/should pay is useful.

Thanks in advance to anyone who reads this, and thank you for being as passionate about gaming as I am!