Good to see the winery I work at mentioned here
A nice drinkable clean skin is always a bargain cooking wine. Unoaked if you can. Dont go putting a $40 bottle in your cooking, but it should be something drinkable.
Im a Riesling fiend so my recommendations are Clare and Eden Rieslings (Pauletts, Skillogalee, Kilikanoon, O'Leary Walker, Hutton Vale, Pewsey Vale, Grosset Polish Hill (if you can get your hands on it))...with some good stuff coming out of WA as well (Larry Cherubino, Howard Park). Theres some real good Hills wines as well which dont have the public profile (like Nepenthe for example) but are superb - The Lane in particular, but also Ashton Hills, Bird in Hand, Shaw & Smith, Pike & Joyce.
For reds, I love Cabernet, so a lot of Coonawarra (Leconfield, Zema Estate, Balnaves, Wynns, Majella), Marg River (Voyager Estate, Ashbrook, Sandalford, Vasse Felix) and Yarra Valley (Giant Steps, Toolangi, Tarrawarra) Cabs get my juices flowing. I think Clare has underrated Cabernet as well. For Mclaren Vale id be looking at Hugh Hamilton, Primo Estate, Shottesbrooke, Mr Riggs, Paxton, Pertaringa for some good Shiraz.
Theres a lot of average cheap plonk out there...but theres always some real good finds if you can be bothered seeking information and trying plenty of wine.