Certainly the Nissan VQ wins all the awards but I have a soft spot for the VG30 and 33 which was used for 2+ decades in Zs, Pathfinders, Xterras, and such. A 60-degree iron block with main bearing caps in a frame, aluminum heads with a single overhead cam and hydraulic lifters. Yes, it had a cam belt, a few issues with exhaust studs breaking and was a bit thirsty but was reliable, smooth and easy to maintain.
V6s really are a compromise as regards dynamic balance. It's only advances in engine mount technology and a desire for compact packaging that made them practical.