I've always been an advocate for New Zealand Chardonnay from the East Coast - Gisborne and Hawkes Bay and some rare exceptions of other NZ wine regions but, having worked for an international wine company and marketed lots of brands from other countries have had great experiences with outstanding chardonnay from Australia, France and of course USA.
I would taste these wines as part of my job and, using the wine allowance I had purchase the best of them. Some great chardonnays that I've enjoyed include: Taylors St Andrews, Leeuwin Estate Art Series, Hardy's Eileen Hardy, Penfolds Bin 14A, Mondavi Reserve and various Meursaults and Montrachets from Burgundy.
I didn't buy other American chardonnays in New Zealand however as, due to the cost and unfamiliarity there weren't a lot to be found on shelves. It was a treat living in Canada and seeing a fairly wide range of 'affordable' Californian chardonnays that we were able to experiment with that the taste profile has been ingrained in us.
Back in NZ the choice hasn't been as great but we buy a lot of our wines from on-line sellers like Advintage, Fine Wine Delivery Company and Blackmarket and there have, over recent years been some good offerings with deals on case loads. We've purchased various Robert Mondavi brands, Chalk Hill, Matchbook, Gnarly Head, Pacificana and others and have enjoyed them all.
Her Indoors is more of a fan than me, liking the rich and luscious characters. I guess as she likes Pinot Gris (I don't touch the muck) the flavour profile is more familiar with the unctuous tones.
Oaked Californian chardonnays are rich and full-bodied with very prominent buttery, vanillin and even caramel characters. The best will have nice stone-fruit, tropical fruit or citrus flavours beneath this. I still cling to my love of Hawkes Bay chardonnay with lots of citrus and stone-fruit flavours and, if nicely (and expensively) oaked tend to have a French-like character. Sometimes, if the wine I've bought is a bit too lean I'll improve it by adding a dollop of an American chardonnay that Her Indoors might have opened.
Our most recent Californian chardonnay purchase is Sebastiani North Coast 2017.Her Indoors buys this by the glass whenever we dine at the excellent The Quay at the Basin in Whangarei and asked me to track down and buy some for her. I did and found it at Fine Wine Delivery Company and had a case delivered. We had a bottle last night and it didn't disappoint. The wine has lovely tropical and peachy fruit flavours under rich and creamy oak characters showing barrel fermentation.
This is great drinking at about $19 a bottle.
As we had a visitor staying I just had a small glass of it, leaving the rest to Her Indoors and the visitor but I did top up and improve the Giesen Hawkes Bay chardonnay I was drinking with a generous splash of it.