In descending order by price:
Rombauer
Mer Soleil
Newton
Belvedere
Toasted Head
Columbia Crest Grand Estates
The buttery flavor you enjoy is due to malolactic (or ML) fermentation malic acid is converted to lactic acid. Malic acid is tart, lactic acid is rich and buttery. Combined with oak aging, it creates the wine you like.
Increasingly, Chardonnay winemakers are going away from ML and oak, but the above wines have it in spades.