Well first I wish you a great trip. Been to Maui many times and it's always been amazing...traffic gets worse every year but what can you do. Some of my favorite places to eat. Hali'imaile General Store...sounds weird but excellent pretty expensive though, Mama's Fish House and Sansei are well known places that are great. I usually stay near Napili Shore so Lahaina is close and has lots of good places that are more casual and better priced. So if you are in Lahaina try Ono Taco, Shark Pit (food truck...hope it's still there) and Local Food (for some authentic Hawaiian). We would get food to go and then hang out at Banyan Park...if you've never seen a banyan tree you got to check it out. The Outrigger Napili Shores Resort restaurant has the best onion soup I've ever had...rest of the food is just ok but I always go there for the soup...it's crazy. Hope it's still as good as it use to be.  Have fun!!

Lucky you!

I usually stay on the SE side (Kihei, Makena), so my recs would be from there:

 
Koiso Sushi (Kihei) is really good.
Nick's Fishmarket is also great, with good views!
Maui Thai also is good.

Avoid the hotel restaurants as much as possible and get out and about!  As others mentioned, look for some of the food trucks- there's one that does awesome fish tacos, Korean-style (Gogi?).  

Have fun!

Try Lucky Belly ... or Town.  Both are terrific.

Erik's Seafood Grotto in Lahaina on Maui is one of my favorites.  Have fun Aloha

Have a Wonderful Birthday
Maui is fun, take the road to Hana rent the tape , Swim in the Sacred Pools
Ive enjoyed Pearl-

Nobody has suggested Longhi's in Lahaina. It is our favorite place. We have just had dinner there but we hear that the breakfasts are the best

BTW, Happy Birthday