As my parents live there and so did i for most of my life I guess you'd think im qualified to answer but my knowledge of decent restaurants is not that great. The annoying thing is that thefew that are by the river arent the best.
Theres a bar n grill (Smollenski's I think) right on the river but I have no idea what its like. The other places are basically pubs/bars that are on the river.
Other recomendations tho that def are worth a visit are Tangawizi , just over the bridge towards twickenham on the right , amazing new curry restaurant , Michelin star and all , quite small but great food and a much cooler vibe than the average curry house.
Cafe Mamma is at the North end of Richmond past the station and over the roundabout on the road that goes to Kew. Lovely Italian family resturant , we go there a few times a year for family get togethers etc as its tried and tested.