Obvious HP although it's true that he does occasionally make some interesting decisions (although not always good.) The best I can say for him is that he's sometimes pretty good on free speech and the First Amendment, moreso when his buddy Scalia was around because Scalia was actually pretty strong on that in general, which elevates him a bit over Alito, by far the worst Justice.
Was Scalia the one who wrote that he desperately wished bans on flag desecration were constitutional, but it just wasn't so?
I didn't read his Texas v. Johnson decision but he was the only conservative to rule in the majority on that one so it's possible.
Brennan wrote the opinion, Scalia joined it. The concurrence in question was from Anthony Kennedy, who also joined Brennan.