Considering that Get Backers' artist is a self-admitted Yaoi Fanboy, the mind-boggling amount of Ho Yay is entirely unsurprising, and very much intentional.
You can pair anyone with anyone in this show. Seriously. Most notable are Ban/Ginji and Kazuki/Juubei.
It might be interesting to note that Ginji actually humps Ban in the manga briefly (though, granted, Ginji was under the influence of Himiko's Devolution scent). After Ginji returns to his senses, Ban exasperatingly says that they should both forget that even happened.
When Ginji starts getting strangled by Hishiki in episode 8, Ban's the only one who senses he's in danger and immediately rushes to his aid while everyone else shouts after him in confusion. Adding to the subtext is that Madoka experiences the exact same thing when Shido's life is in danger in the very same episode. And Shido/Madoka are an Official Couple.
Kazuki's gang, Fuuga (lit. "Elegance"), is really into the Ho Yay. There's some kind of Toshiki/Kazuki/Juubei Love Triangle, apparently; Toshiki even attempts to Murder the Hypotenuse, claiming that Kazuki never paid any attention to him when Juubei was around... You can probably throw in Saizou, too. The only gang member who doesn't act like Kazuki jilted them at some point is probably Sakura, Juubei's sister.
Combined with one of the intros showing Juubei and Kazuki represented as needle and (red) thread (their respective weapons) it's pretty solid.
Then there's Juubei's passionate declaration that he was born to protect Kazuki, a shot of them in a desperate half-embrace, half-serious-personal-space-violation in the third ending sequence, and Ginji even says they act like they're on their honeymoon. Also lampshaded by Emishi
Takuma Fudou's one-sided obsession towards Ban. Which also overlaps with Foe Yay. Yes, it's very disturbing and very wrong... but it's undeniably there. And not very subtle, either. After Ban ripped his arm off, Fudou became totally obsessed with him. He actually kept his own rotting, maggot-infested arm with him just so he can remind himself of Ban - which made him feel "incredible chills rising up throughout his body." It gets worse: His passionate dialogue towards Ban includes how he has a "throbbing desire" to kill him, as well as screaming for Ban to "give his body to him," "meet his desires," "quench his thirst and let him enjoy himself." And when Ban starts worrying about his Heterosexual Life Partner Ginji, Fudou gets pissed. "What are you looking at?! Look at me, Takuma Fudou!!" This is taken Up to Eleven in the Birth Arc, where Fudou reveals his dislike for Ginji, even coming straight out and saying that it's because "when you're around, Midou doesn't even notice me. Midou's eyes are not on me... because you're around!" He then proceeds to try to kill Ginji so that Ban will pay more attention to him. And then there's how he tells Ban that his mind goes blank whenever he sees him, and he can't remember anything other than trying to make Ban give his body to him and meet his desires. It's probably worth noting that he also got majorly pissed at both Hevyn and Shido for interfering with his fight with Ban, and for Hevyn gently putting a shirt on the half naked Ban (an act which seemed to piss him off to the point where he went berserk). Another noteworthy scene is during the Birth Arc, where Fudou gets very restless and excited, and feels a great "desire," wondering what it is about this day that he senses is so exciting. It then cuts to Ban sneezing, and exclaiming happily that a big breasted babe must be thinking about or talking about him.
As well as an instance where, when Ban wasn't putting up enough of a fight, Fudou started cutting himself up on the chest, screaming at Ban to "make him bleed" and "push him to the edge."
Though Fudou's death scene was kind of sweet... in a weird, warped way. He confesses to Ban that he's happiest when he's fighting him, and that he wishes that they could go on like this forever and ever. And Ban, on the other hand, ended up using up his Evil Eye so that Fudou could have a nice dream before he died, of them continuing to fight. Ban's expression when he gently closed Fudou's eyes was actually pretty emotional and filled with compassion.
You really can't miss the Ho Yay, even if you're not into it. I mean, when OFFICIAL ART has Ban feeling up Ginji and the latter wearing nothing but a dress shirt... there's not really much to leave to the imagination. And that's not even starting on Kazuki's art...