Tone with sarcasm or with compliment?

Would depend entirely on tone of voice - and context. Could be either a very complimentary statement, or a derogatory one.

Funny can be very good, too.

As far as I am concerned, there is but one example which proves "funny" can be very good:
When speaking of a joke, the audience remarks: "very funny!". It is a compliment no doubt.
I'd like to know if you think so.

No, I've said "Very funny" with a contradictory expression to my husband when he's told a baaaaaaaaaaad joke.

The problem with sarcasm is that it is often in the intonation and expression. The same exact words, printed on the screen, can be straightforward or sarcastic.

I've definitely seen people use "she's a riot!" in a complimentary way. ("Have you met our new receptionist? She's a riot!")

With contradictory expression, you could say "very good" or whatever.

Yep. I have often heard "you are funny", or he/she is funny used as a compliment Oristar - I am not sure where you got the idea that it is normally derogatory. It CAN be - again it is all in the tone.

How bout'n if you are "Special" ???

Saying you're a riot can be meant in both ways. I usually use it to compliment someone or something that I think is funny, but if someone said something to me that I didn't like, I may also respond by saying "oh yeah, you're a real riot!".

Not to mention those who, at least that I have met, used to jeer at others with the word "funny", let's see the definition of "funny":
Funny
adj.
(1) Causing laughter or amusement, e.g.

He has funny habit of blinking when talking with others.
(2) Intended or designed to amuse, e.g.
A funny joke.
(3) Strangely or suspiciously odd; curious, e.g.
It's a funny thing, but she put the ring on the dressing table a few minutes ago, and now it's missing.
There's sth. funny about the telephone; it won't work.
What can that funny noise be?

(4) Tricky or deceitful, e.g.
Don't get funny with me.
They had got together the whole evening, and I knew there was something funny going on.
(5) Sick, e.g.
She felt a bit funny.

So the word seems mostly a derogatory adjective, while the word "interesting" just means:
Arousing or holding the attention; absorbing, e.g.
An interesting story book for children.
In an interesting condition [situation].

Things will develop in the opposite direction when they become extreme...

OristarA
Very true.