Interesting, and I've asked this question before (in my social circle), how some answers are based on when you first started reading comics and other answers are based on random years.

For my choice, there was a lot going on that year. The second version of EAGLE COMIC had launched in 1982, but in 1990, it became full colour - and gave us the original Dan Dare back. So from 1990, I was buying the new EAGLE, the UK DC reprints and a few US titles. So 1990 was an eventful year for me.

And what a year for films, too: HOME ALONE, TOTAL RECALL, GOODFELLAS, ARACHNOPHOBIA, THE WITCHES, DIE HARD 2, etc.

I wasn't short of comic or film entertainment during my year of choice. 

- New Mutants by Claremont/ Sienkiewicz

...

Excuse my pedantry, but I'm pretty sure Sienkiewicz had left the book several years before '89. I was barely reading Marvel by then but had followed entire his New Mutants run.

1984 for me.

I've recounted this story on another recent thread, but I was 14 and went to France with my school as part of a two exchange programme. My maternal grandmother bought me a Marvel comic for every day of the trip so I wouldn't get lonely and I recall it being quite a haul - Sue losing the baby in FF 267 and the arrival of the Hellions in New Mutants 16.

I enjoyed DP7, too, although it was impossible to get hold of (I found some back issues at a car boot sale).

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Add me to the list of those that enjoyed DP7. Definitely my favourite and most consistent of the New Universe titles - I managed to get hold of loads of issues in my LSC bargain bin while the run was ongoing.

Excuse my pedantry, but I'm pretty sure Sienkiewicz had left the book several years before '89. I was barely reading Marvel by then but had followed entire his New Mutants run.

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I was thinking the same thing, Matthew but then noted he was in Brazil and likely got the titles content much later through Brazilian reprints. I've noted several instances of that throughout this thread from folks who read the stories I read a few years later through foreign reprint versions. 

And, David, yes to all those other 1986 titles I forgot, especially Son of Ambush Bug, Swamp Thing, and the Stern/Buscema/Palmer Avengers (I also loved the Official Handbook and Who's Who when they were coming it and used them as reference guides for drawing those characters). The Avengers run in particular is my favorite run of Avengers ever despite not even being my favorite lineup of Avengers. Roger Stern is such a great writer and that Buscema and Palmer art team was just gorgeous. 

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It's a bit like how the UK DC reprint SUPERMAN title reprinted MOS in 1988. I'd read it in 1986, but anyone coming aboard that title in 1988 would associate '88 with MOS even though the US published it in '86. 

It's also like how Panini (the successor to Marvel UK) are reprinting many titles now, some of them from 2-3 years ago. It can be confusing if I chat with someone from the US because I may mention the "new" Wolverine (Laura). Her exploits are new to me but the current reprints are, I think, from 2014 or 2015. So from the perspective of an American, they aren't new even if I describe them as such.

Also, when the UK Batman title began (BATMAN MONTHLY was its name), it was 1988. But it initially reprinted late 70s Batman tales. For a Brit, those tales were "new" but if they'd mentioned that to an American, the American would have said, "I was reading those ten years ago." :)