Actor Allusion: Towards Avatar, Angel and various other things other people did.
The Vegas episode combines Boreanaz's role of Angel (who also spent time in Vegas) with a role Angel himself played as vampire stuck in the fifties, rat-pack style. Booth spikes his hair up, dons greaser clothes and suspenders, faking a Bronx accent outta Guys and Dolls.
Booth, like Angel before him, feels that he has to atone for the lives he's taken as a sniper.And they both play detective style roles.
Ascended Fanon: "Squintern" was a fan term referring to Brennan's six ever-rotating interns. The cast and crew have recently adopted it.
Dawson Casting: Zach is supposed to be the youngest member of the team by a significant margin; in fact Eric Millegan is the third oldest member of the cast after David Boreanaz and Tamara Taylor.
Friday Night Death Slot: Since mid-season 2013, and at least one person at Entertainment Weekly magazine thinks the show will end in 2015. According to the Friday Night Death Slot page there's already a few bad signs: it's on FOX, it's not family-friendly, and it's on FOX.
McLeaned: Vincent Nigel-Murray is killed in "The Hole in the Heart" a few weeks before Ryan Cartwright's new show was set to premiere. The dialogue during the death scene even sounds like someone who's likelier to be fired than died.
Simon Lee before being a mole in the CIA for Sophia, was training to be an astronaut. Probably to get him back to his home planet. (YMMV on whether Ian Anthony Dale is currently big enough now to warrant this.)
Also in the pilot, Sam Merlotte tried to set Brennen on fire.
Hardison plays a shell-shocked veteran in Season 1 and Phil was Brennan's publisher's assistant.
Kaiden Alenko is the private eye Angela and Hodgins hire to track down Angela's former husband in the first episode of the third season.
Trolling Creator: Executive Producer Stephan Nathan seemed to really be enjoying how much the fans wanted to kill him for the season 8 finale. His response to being told dropping Pelant like a nuke on the B&B engagement was "not right" was to laugh and call it "so much fun to do."