I haz teh fans so badly that I am at the moment working on a "Red Pineapple" tee-shirt for myself to wear under my kuk sool uniform. It's going to have to be a negative of the "original" since we have to wear black tee-shirts, but be warned: when I am doing forms, be scared. I'm imagining myself as Renji Abarai, the Red Pinneapple of DOOM!

Also, as I was searching through the vast wasteland of the Internets for a picture of Renji in this particular shirt, I came across his Wikipedia entry. Now, I feel the need to defend him. You KNOW, he may have lost to Byakuya Kuchiki, but that's only because Byakuya is a big, fat cheater. I want any Renji detractor to go back and watch the episode/read the Manga of that fight. Here's how it goes in a nut shell.
Byakuya: "Renji, where are you going?"
Renji (paraphrasing): I'm savin' Rukia and you can't stop me.
Byakuya: "You may not." (Note snottiness already present.)
Renji: "I will!"
Fight ensues. Byakuya tries out his tired old flash-step trick and Renji (who still can't entirely see it), still manages to deflect it because Byakuya is so f**king habitual, he does the same move every time. Thwarted, Byakuya goes shikai. He's all "Scatter, a Thousand..." --oops, Renji's sword crashes into Senbonzakura and knocks the shikai out. Byakuya gets his WTF look (slightly more opened eyes) because Renji didn't have to call Zabimaru's name, and tries to ask Renji if this means he's achieved bankai, and Renji says (basically) "Check it out. My bankai is going to drive you to your knees." Byakuya is all snotty about it, tries scattering the thousand cherry blossoms again, but Renji is totally unscathed. Zabimaru achieves its stated goal. Byakuya has to pick himself up off one knee.
Things are looking good for Renji, right?
In a fair fight, yes. What is Byakuya next move? Anyone? Anyone? Bueller? Right, magic. Not, let's go man-to-man, sword-to-sword. No! Byakuya uses binding spell number 33, which Renji manages to mostly deflect but this leaves him open to... ANOTHER MAGICAL ATTACK, binding spell 61, which completely immoblizes him.

See this?
Are you following how dishonorable this is??
Renji can no longer fight. He's been spelled at a really high level. He is peirced with "six-rod light restraint."
It's also a fairly well established in the story at this point that Renji has some magic, but it's not his main skill set.
So, as his captain, Byakuya knows this. It's like you and your opponant both have swords (you're equal there), but you also have a giant laser gun, while your enemy has a pea-shooter. Fair to use the laser gun?
I think not!
Because, now that Renji is utterly helpless, Byakuya decides it's a good time to pick up his sword again. His opponent can't move a muscle. Can't lift his sword in defense, and Byakuya isn't satisfied with a swipe or two, no, he goes ninja on Renji's a$$, and rains a million sword-pettles down on him (his bankai).
THEN, when Renji is laying on the ground, completely torn to ribbons, Byakuya has the nerve to give Renji a lesson in "class." He says the difference is that Byakuya is much more noble and pure and awesome than Renji could ever even hope to imagine being. In his amazingly rude lecture, he tells Renji that there was never any way to win this fight because Byakuya is just that much better, he's too high up for Renji to even consider going after.
Seriously?
How would he know? He never let Renji fight! He tied him up and hit him with a cannon.
What makes Renji even more awesome here is that, he doesn't just lay there. He just got completely plowed (unfairly), but he gets up and goes again, even though his bankai is shattered and has returned to its sealed form unconsciously. Picture a regular katana now. When he gets to his feet, Baykuya nails him (almost literally) with more magical swords.

Is Renji done? No, he pulls them out of his body, one by one, and goes after Byakuya *again*. Only then, after actually scratching Byakuya's cheek, is he finally down for the count.
I think, without magic, Byakuya would have been pulverized.
And, I think Byakuya knew it the second Zabimaru drove him to his knees. What annoys me, is that Byakuya gives far more respect to Ichigo in their fight, moments later. He doesn't resort to magical restraints until much deeper in.
So, okay, Renji gets his butt handed to him a lot. But, at least one time, it wasn't a fair fight.