Excalibur featured in other books
I'm going to try to compile a list of other comics in which the characters from Excalibur appear, as the team Excalibur (not just every book each individual was in). I'm doing this from off the top of my head, and anyone out there who knows more, please add to the list. I'll update as I think of or come across other issues, too.
Thank you!
- Marvel Comics Presents #5: contains a short story of Excalibur during the Cross Time Caper, after they left not-Barsoom (from issues 16-17) but before they reached Jamie Braddock's racing world. Kurt and Kitty centric, very cute.
- ClanDestine vol2, issue 3: Excalibur is even on the cover! These books are written and drawn by Alan Davis.
- X-Men Unlimited 19: recently summarized in a post by me, this one is heavy on Kurt, but features cameos by Kitty and Piotr; finalizes a plot point that is otherwise not addressed in Excalibur, regarding the fate of Kurt's foster mother Margali Szardos after the story Devil Under London.
- Excalibur: Weird War III: technically it's an Excalibur book but it gets forgotten for reasons that become clear when you read it. It's just not super great.
- The recent Marvel Comics 85th Anniversary Special: another Excalibur story, written and illustrated by Alan Davis (very fun, very cute, a friend said it's like going home and it was!)
- X-Men Legends, issue 12: an Excalibur story by Chris Claremont (contains a few mistakes in some details but still neat to see Kurt and Kitty together; focus is on those two, set before the team is together)
- Captain Britain and MI13, annual #1; the story is mostly about Brian, but there is a hint of Excalibur in it.
- Dark Angel issue 6: The team is asked to help Dark Angel deal with some kind of monster killing people out on the moors.
- Marvel Comics Presents 101-108 "Male Bonding:" Focuses solely on Kurt, with an appearance by Wolverine; takes place between Excalibur issues 54 and 55.
- X-Men vol.2, issue 80: features Kurt, Kitty, and Piotr leaving Muir Island after Excalibur has disbanded
- Marvel Comics Presents 31-38: short chapters as they fight knockoff Loony Toons (thanks, @phoenix for this addition!)
Two more I can think of are She-Hulk #26 (Jennifer is on a transatlantic flight when she's attacked by a mind-controlled Brian, teams up with Excalibur to free him) and Thor #427-428 (a villain bewitches Brian and Kurt with a magical prybar into thinking that Thor is the Juggernaut, and they all fight).
Both appearances take place between the last two issues of the St Searle's arc, when Kitty has just reunited with the team but before her school is saved. The Thor issues are mildly internet famous in comics circles for featuring that time where Kitty went from zero to horrifically murdering an Avenger with almost no escalation.
ETA: Excalibur also appears, in their Muir Island era, during one of Wolverine's feuds with Cyber (Wolverine vol 1 issues 80 - 82)