For a long time I had a pretty ambivalent opinion of Grant Morrison. While I liked Zenith a lot, I felt that on the whole his influence on 2000AD led to a disastrous decline in quality (Big Dave, ffs!). I appreciated his work he on Doom Patrol and Animal Man, but I felt there was a lot of acting up in those books that was less to do with a commitment to a fictional vision than about freaking the nerdy comics norms. I thought that The Invisibles looked like pretentious crap (I only lasted a few issues before chucking it in).
Recently, however, I've been re-assessing him. I think it started with reading his Kid Eternity update for The Zone a few years back. I remember rolling my eyes at it when it came out and giving it a swerve, but reading it for the first time at a couple of decades remove, I was struck by what a solid piece of work it is. There was a still a bit "ooooh edgy!" going on, but to be honest that looks more prescient than wilfuly obnoxious now.
What really impressed me was his control of the fractured narrative - he'd broken it apart in a way that was a little hard to follow, but, with due attention paid, made rock-solid sense. He wasn't just showing off, he knew exactly what he was doing!
At about this time, I was getting back into supers comics after a period away from the genre and one day in the comic shop my kid asked for Batman comic. I ended up getting him one of the Morrison issues (it was the latest one out at the time - about 650, IIRC). I'm not really a fan of Batman as a character, but I read it and was really impressed by it. It was a cool and interesting story (ending in the revelation of Damien Wayne) and I checked the writer - yep, Grant Morrison.
Now, I'm not really big on the DC characters, for various reasons, but I've been following Morrison's work at DC every since. I thought 52 was fantastic and Final Crisis was genuinely brilliant. I bought up the Seven Soldiers trades and loved them to bits.
I've been reading his Batman regularly since the Batman RIP storyline offered a nice hopping on point, and his work on Batman & Robin is first-rate. It doesn't matter that I don't like Batman much, as Batman's not really what it's about - it's all pure Morrison mind mess and crazy super-hero fun.
This little puff piece on i09 makes a couple of interesting points about the Batman character, but also about Morrison's approach. I particularly liked this:
Comics can do a lot of things that movies can't do, and vice versa. It's a shame when so many comics are storyboard-style, low-budget pitches for movies. Let me see the weird stuff.
This is why Grant Morrison is a brilliant comics writer: he loves the medium and he understands it. That's all any writer really needs.
(NB: I thought this little critical piece on Morrison from i09 a couple of weeks back was also pretty interesting, but I don't have much to add.)