Day 21: The seiyuu with the most acting range
One of those girls who can do boys, so, obviously and once again Maaya Sakamoto.
Day 22: The seiyuu with the least acting rangeDunno. Ah well, maybe Norio Wakamoto. But he can do GPS voice so ...
Day 23: Cool dude seiyuu
As in, I'd like to be their friend? Tsuda Kenjirou!
Day 24: A seiyuu you make fun of
That's really mean but Kondo Takashi (Claude in IkoMei) Not that he's a bad actor, quite the contrary actually, but how he moves, talk, laugh and such, it's just ridiculous and exagerated, in the bad sense of the term.
Day 25: A seiyuu that makes you like any character they portray
There are a lot, and considering my tendancy to like all kind of characters, especially the most twisted and unloved, without the involvment of seiyuu I guess it doesn't matter much?
But if you really want me to tell then I'd say Hochuu Ohtsuka (because he does Davy Jones' voice in the Japanese dub of Pirate of the Carribean and since then I find him sexy. Yeah. Sexy.)
Day 26: A seiyuu you’d hang out with
Tsuda Kenjiro again!
Day 27: Best seiyuu match-ups
I'm not too sure I got the sense of the question so let's say it's as in : do a great job together.
Actually the first "match ups" I thought about were into fujoshi territory so I'll shut up and instead will tell you that I think Kana Hanazawa and Nakamura Yuuichi were pretty awesome together in Oreimo.
Day 28: Best seiyuu match-ups, romance edition
SUZUMURA KENICHI AND MAAYA SAKAMOTO!
Come on, they're married! And everyone who watched Kara no Kyoukai was rooting for Mikiya and Shiki.
Day 29: Your least favorite seiyuu ever
Day 30: Your favorite seiyuu ever
And overall, it would seem I talked on and on always about the same seiyuu, I'm really sorry, I love a lot more of them but these questions didn't cover a wide range. Sadly.