I have spent a lot of my time at Tahbilk Winery in Nagambie... and I am a huge fan of a lot of their wines... but the two main picks are this Shiraz and their Marsanne (white wine) If you haven't already tried them... I suggest you go out and get them now!
Redbank winery is near St Arnaurd and I always find it the oddest place for a winery! But they produce snappy little cheap wines that are very worth drinking! All their reds are easy drinking and for under $10 great value! The sparkling they have is also really nice and not too sweet.
I LOVE Chapel Hill Winery, It is probably my favourite in McLaren Vale (Apart from Samuel's Gorge - but they don't have anything under $15) Anything Chapel Hill is always the best quality and this Cab Sauv is no different... at $16 it's just a fantastic wine and HAS to be on your "to try list"!
The next two wines are from St Hallett's winery in the Barossa... both are under $15 and very in the Barossa style... big, rich and best had with food. The first is my favourite "Faith" and I have faith that you to will enjoy it!
Wynn's Coonawarra Shiraz is a wine that year after year it is exactly the same... just the way Foster's like to make their wines. There is nothing particularly exciting or different about it, but in a pinch it's worth the $15
I used to love d'Arenberg wines, then they changed wines makers and now their wines have too much sulfur and are very bretty (not a very nice wine yeast) but for $12 this is still a pretty good blend... just make sure you give it plenty of air (either decant it or just pour it back and forth into a jug) before drinking it