Prickly bastard he can be at times or not, Yamato has those he is close to. This is NOT every Chosen Child's relationship with Yamato broken down, instead this is what I saw as his closer friends. Do enjoy my lovely psycho-analysis...which is more psycho than analysis.
These guys are best friends. It's especially obvious in 02, even though they don't really hang out much. Yamato's relaxed in Taichi's company and they have each other's backs.
From what I can surmise, Koushirou, Taichi and Yamato are a trio who like to buddy it around at school. They seem pretty good friends (ie, they all went camping towards the end of the Digimon Kaiser) and they make a perfect team, don't they? Koushirou's the smart one, Taichi's the headstrong one, and Matt's the quiet one.
Sora's everyone's friend, and the Sorato Nazis will hang me if I don't include her, but, still. Yamato and Sora work well together as friends because they tend to think the same -- while Taichi thinks about the now, Sora and Yamato oftentimes think ahead. Sora has a quiet trust placed in Yamato.
I know, you probably think I'm nuts, but bite me :P I think Daisuke looks up to Yamato and respects him because he's friends with Taichi, and Daisuke thinks Taichi can do no wrong. Although they started off on a bad foot, I'm pretty sure they get on okay now.
Ken and Yamato, towards the end of 02, really struck a chord with each other. They seemed very relaxed and open in each other's company. I think maybe Ken saw in Yamato someone who's felt almost the same pain as he did in the past, and naturally felt a special bond with him.