I have booked Ariel's numerous times and have never been disappointed. I LOVE the tri-tip. I think that character meal is one of the best values out there, but I was always able to get good voucher prices through
AAA. We actually spent less on an Ariel's meal than we did at most other sit-down places, and the interaction was fabulous!!
OTOH, I've not had good experiences at Goofy's (though others have) and I won't spend that kind of money again for it, most likely. I've not heard good things about Minnie's overall so I'd be cautious with that one. It's hard to know, though, because I've also read terrible reviews of Ariel's (mostly in the past), but we've had...well, I think about 8 dinners there and every one was wonderful.
I have to agree with the PP who said that the food at DL, overall, is pretty awful. There are some things here and there that are good but most of the food is mediocre at best and relatively expensive, so paying $15 - $27 each (which is what I've paid with vouchers) for a character meal at Ariel's seems like a pretty good deal to me, since it includes appetizers, salad & bread, dinner, dessert, drinks, tax, and tip.
Whatever meal you choose, have fun!