Just ate lunch at Funcho's yesterday. I really enjoy their fish taco, chicken taco and the "palta y pollo," which is grilled chicken, rice, onions, guac, cheese and sour cream in a burrito wrap. The main thing I dislike about the place is the cheese - really bland - so any dish that has a lot of melted cheese - like nachos - is not that great. That said, it's a good lunch place where you can sit outside and grab an ice cream afterwards at Snowflake, right next door.
The pizza at Roadhouse is good, the "grandma" pie/slices are very good. It is located on Rt 25 somewhat east of the Mill Road traffic light and a little east of the other 2 places you mentioned. I think they are closed on Sundays.
Funcho's food is good, but you will have to see if you like the style. I'm not a burrito expert, but I think they are what you call mission style, with some rice in the filling. The burritos and wraps are over 1 lb but can run $5-9 depending on fillings. The right hot sauces are available on the side. They also have a large number of variations on enchiladas, tacos including fish tacos, salads, wraps quesadillas, etc. They have another location on Main Street in Westhampton Beach.
Snowflake is the best. It is next door to Funcho's and the parking lots connect.
Snowflake has great home-made icecream. The place is a landmark. Excellent!
Funcho's is a wrap bar. Poor ambience and I wasn't crazy about the service or the food.
The Roadhouse seems to do good business, but the night that I was there, there was no air conditioning. It gets hot in a pizza place. The food, as I remember it was OK.