Yay, surveys!
Which episode of the entire series do you believe is the best?
Oh, why must you tempt me?! Seriously, this show is filled with so many great episodes that it's very hard to choose just one, but if I was forced to choose one at gunpoint I guess I would go with "Good Wilt Hunting" as well (tv movies count, right?). I just thought it was extremely well-done by the Foster's crew since it answered so many questions about our favorite tall, red, basketball-playing imaginary friend...not to mention how the humor and tender moments balanced out quite nicely. If I could give an episode a perfect 10, this one would definitely deserve it.
Other honorable mentions would go to "A Lost Claus" (It would be my second pick, actually), "Frankie, My Dear" and "House of Bloos".
Which episode of the first season do you believe is the best?
This is another difficult choice since there are so many great episodes from this season. I think I will go with "House of Bloos", though, because it was a great way to start the series. It really gave us all a general idea of what the characters' personalities were like instead of just throwing in some random characters without any depth or personality almost as if we were expected to care about them regardless (a major problem I had when I watched the Squirrel Boy premiere last year, by the way. Yes, I tried to give this horrid show a chance! XP). It also had a slight sense of epicness that I don't see in many children's shows since Mac and Bloo had to go through a few life-changing experiences when you think about it (Mac was so used to having Bloo at home all the time and I'm sure that Bloo himself was used to this as well. You can't tell me that nothing changed for them when Mac had to take him to Foster's!).
Honorable mentions: "Store Wars", "World Wide Wabbit", "Berry Scary", "Adoptcalypse Now" and "Blooooo"
Which episode of the second season do you believe is the best?
Ah, another good season of Foster's. I think I'd give this one to "Frankie My Dear" basically for the same reasons as many others would. Plus, I liked how it looked into Frankie's love life and all of the supporting characters were hilarious. It was also the first time we ever got to see "Orlando Bloo", so how could I NOT love it?! XD
Honorable mentions go to "Partying is Such Sweet Soiree" since it would've come in a close third only behind the one I mentioned earlier and "Sweet Stench of Success", which would also make it into my honors list.
Which episode of the third season do you believe is the best?
I'm definitely going to give this one to "A Lost Claus". Like I said in another thread somewhere on here, this episode definitely had a major "Charlie Brown" vibe going in some areas and the humor was sublime, especially the Bob Marley gags.

But what really got me was the touching message that was found in the episode. When Mac begins to lose faith in the idea of Santa Claus, but ends up keeping that faith when he gets what he secretly asked for at the end of the special (remember the underwear?! XD), I must say that deep down I believe that this was obviously representing the idea of never giving up hope or faith if you have a strong belief in what you are doing or feeling (whether that would be miracles or even a religious faith could be up to the viewer, I suppose). Sure, some of that was humorous, but I think it was meant to be a bit deeper at the same time.
Honorable mentions: "Eddie Monster", "Camp Keep a Good Mac Down", "One False Movie" and "Cuckoo For Coco Cards"
Which episode of the fourth season do you believe is the best?
Well, I would say "Good Wilt Hunting", but I'm going to go for something else to "spice things up".

Instead I'm going to go for "Bus the Two of Us" simply because I found the humor to be really great in it.
My honorable mention goes to "Squeeze the Day" because I found it to be almost as funny as "BtToU".
Which episode of the fifth season do you believe is the best?
Well, this one is not going to be as accurate as the others because I still haven't seen all of the season five episodes yet!

(I missed "Schlock Star" and "The Bloo Superdude and the Magic Potato of Power" since I was either doing other things or doing college work during the time they aired) However, so far I'm going to jump on the bandwagon and say that "Affair Weather Friends" is the best one I've seen so far. The episode was already enjoyable to begin with, but Berry's return was unexpected (although I probably should've seen the plot twist coming I actually didn't! It was a shocker to me! And was it just me, or was Berry, like, ten times as psychotic as she was in "Berry Scary"?

) and that made it all the more exciting for me.
Which of the five seasons do you believe is the best?
While I like all of the seasons of this show seasons one and three hold special places in my heart. I would probably pick season one over three, though, only because most of my favorite episodes happen to be from that season.
Which of the special episodes do you believe is the best?
"Good Wilt Hunting" for all of the reasons mentioned earlier.
Which of the shorts do you believe is the best?
I haven't seen all of these, so I'm not sure which one I'd go with yet, honestly.
Which human character do you believe is the best?
Sooo hard to choose since I think Frankie and Mac are nearly equals, but I think I'm going to go with Frankie only because I can relate to her a little more than I can Mac. But they're both pretty close and probably actually tie when it comes to how they're structured as characters.
Which Imaginary Friend do you believe is the best?
Wilt, of course! My reasons?...they're so obvious that I shouldn't even have to explain them.
Which “minor”, or background character, do you believe is the best?
I'd say Red, but I'm also starting to lean toward "Cherry"...uh...I mean Berry now, too!

I guess I like both of them the same! Seriously, after Berry's crazy schemes in the latest episode I've started to wonder what exactly she was created for to begin with. We all know that IFs are usually created to be a "friend" to a child (and sometimes for even deeper reasons, as we found out in "Good Wilt Hunting" with Wilt's relationship with Jordan.), but what on earth could've happened that caused Berry to become such a rotten apple?