If.

You.

Haven't.

Seen.

This.

Anime.

Watch.

It.

Now.

It's hilariously funny.

It's completely skippable if you haven't seen it, but if you have nothing on your watch list, I suppose it is worth the watch. It's nowhere near the quality of comedy as, say, AssClass, but it is action packed.

Eh, I don't think Assassination Class is THAT great.

Attack on Titan is my favorite anime ever.

You should also read the manga.

UBD uses that pervy humour that always ends up with the man being looked upon in a bad light. It's refreshing to see a pervy girl, but I've seen it all before.

With AssClass, you get, in essence, Gintama-lite, with a better and more suspenseful plot. You have the straight man Karasuma, the semi-pervy and troll teacher Korosensei, everyone's go-to for banter Bitch Sensei, and many various scenes where beating people to a pulp is made laughable.

In an episode of season two of AssClass, almost, if not all, students and teachers are made fun of in a semi-subtle way when they give everyone some funny and sometimes 100% savage codenames. You get hammered time after time with a codename that insults and degrades the characters, giving you 2 minutes of pure comedy mixed with action.

In UBD you get a perverted girl who isn't even a real girl sniffing this dude's underwear, and the dude gets attacked.

I have seen the latter too many times.

UBD has the better actions scenes. They are beautiful and always moving. But a polished turd is still a turd (see: Sword Art Online). Not to say that UBD is bad, just that it has been seen before.