I'm not that fussy when it comes to food in lounges - I'm pretty easily satisfied as long as there is at least something there. My rating of a lounge depends much more on the beverage options and amenities (wifi, showers, views, seating/ability to find seating etc.).
I haven't been to that many oneworld lounges, but my favourite oneworld operated/owned lounges in order would have to be:
1) SYD QF F (by a long, long, long way!)
Fabulous views of the airport and the Sydney skyline in the distance as well as some fantastic food. Good selection of drinks as well - De Bortoli Noble One dessert wine was a highlight when I was there (although I also had a killer espresso martini as well!). Decor/furniture is modern, chic and creates a lovely atmosphere.
2) LHR CX F
Great views of the runway, comfortable lounges to sit back on whilst enjoying aforementioned view, delicious noodles, great shower suites and Veuve Cliquot (a champagne I personally enjoy).
3) LHR BA F (T3)
Comfortable (and uncrowded) seating as well as great views from the First dining room. Taittinger Prelude is an easily drinkable champagne. Very relaxing lounge.
4) MEL QF J (Domestic J/OWE)
Good selection of food, great drinks selection (including my favourite beer VB and my favourite spirit Bundy), nice views of the tarmac. Can get a little crowded sometimes.
5) JFK AA F
Great shower suites, perfectly adequate food, very good drinks selection (Disaronno and Bloody Mary mix are the standouts), great views of the apron and Manhattan skyline. Fantastic friendly staff. Bottled water is an ingenious touch (and hugely appreciated when hungover!
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6) LHR BA F (T5)
If only visits before midday were considered I'd rate this lounge higher due to its amazing (in my opinion) breakfast. Decent drinks selection (^ for bitter lemon as a mixer) and the 'outside' terrace is a nice place to be. Showers are absolutely horrid and seating can be difficult to find during the day.
7) MIA BA/AA Premium (Concourse E)
Good drinks selection (a nice range of beers including some interesting craft ones), substantial food is lacking a bit, but is redeemed by a nice selection of snacks/light bites. Thoroughly enjoyed the big bowls of fresh berries. Very good shower suites (recurring theme in American lounges). Decor a bit outdated.
8) LAX AA F
For some reason I wasn't a huge fan of the layout. Food options didn't seem as good as the Flagship lounge in JFK. I didn't have much time on my transits in LAX so didn't spend that much time in the lounge.
Notable mention to the Almost@home lounge at HEL - a third party lounge that BA uses for CE passengers. Its decor is absolutely gorgeous and is incredibly Nordic in design. A nice selection of food and drink and very friendly staff.
I'm going to Hong Kong in August so I'm looking forwards to trying out the QF lounge, CX Wing F and CX Pier F at HKG (as well as the Al Mourjan lounge in DOH as I'm flying QR/CX thanks to a £1300 exARN J fare)