RE: Is it still funny?
I've heard everything up until Hoenn was great. I've seen a good chunk of Season 1, have the Orange Islands on DVD, seen a few episodes of Season 2, and one or two from Johto. I still need to see all the movies and I've heard they're all at least decent except for the Giratina one which was meh at best. IMO, Sinnoh was horrible. After about five episodes I started to see a pattern that was quite obvious.
Ash tries to go somewhere->Team Rocket steals their Pokemon-> They blast off-> Ash magically arrives at his destination, even though he didn't do any traveling in the entire episode.
Yeah. Too repetitive.
I haven't seen much from Hoenn, but out of the samplings I've had, the only good season from that era was the Battle Frontier one.
Of B/W, I've only seen one or two episodes so far, and they look much more promising than anything after Johto. I've heard good reviews of them too, you should check them out.
To answer your question, Is it still funny, I honestly can't say much. I've not seen anny episodes for a while, so I'm not sure.