Further to what's already been posted regarding the need to narrow the search somewhat, if you could at least specify a country you are thinking of, that would help a lot.
Most recommendations in this thread are new world, which is not what I would look for. If you're interested in old world there are lots of options in that price range as well, some of which are gorgeous. Anything from Georges Vernay, for example. I'm thinking of his Vin de Pays des Collines Rhodaniennes in particular which I got for around $17-18 not too long ago, but he also has a St. Joseph for less than $30 too.
"best" is one tough term; there are some good suggestions here but the styles of same are all over the map. have you had a Shiraz or Syrah previously that was of interest to you? Do you have a wine shop or wine bar near by where you might be able to try a few different glasses of it? The Qupe Bien Nacido was one of the wines that really triggered my interest in wine but it has little in common with, say the Woop Woop (both recommened by vinosnob - and I have no quarrel with those suggestions).
I would have to agree with ibstatguy, take the suggestions here and find a wine bar or wine club in your area where you can set-up a tasting.
I have even called on a couple of high end restaurants here in Toronto that have excellent Sommeliers and wine cellars to set up tastings. These were private one on one experiences where the Sommelier led me through 5-6 wines at a time; same grape different regions different styles. Very helpful and not as expensive as you might think, certainly less than the cost of 2-3 bottles in each tasting I didn't like and didn't have to buy a whole bottle of.
A quick look at BevMo's website...
- Qupe Syrah Bien Nacido Vineyard '06 (750 ML)
Regular Price: $27.99 ClubBev: $22.99
- Beckmen Vineyards Syrah (750 ML)
- Torbreck Shiraz Woodcutters '07 (750 ML)
- Mitolo Shiraz Jester '06 (750 ML)
- Qupe Syrah Central Coast '07 (750 ML)
Regular Price: $17.99 ClubBev: $11.99
- Woop Woop Shiraz '07 (750 ML)
- Jacob's Creek Reserve Shiraz '06 (750 ML)
Regular Price: $13.99 ClubBev: $9.99
Columbia Crest Shiraz Grand Estates '06 (750 ML)
Regular Price: $10.99 ClubBev: $8.99
Here's a bunch of widely available producers selling good, inexpensive syrahs: Eberle, Kendall-Jackson, Valley of the Moon, Mahoney, Ventana, Church & State, J. Lohr, Gloria Ferrer, Concannon, Frey, Liberty School
For a lot more names, check out the results from last year's SF International Wine Competition (sorted by varietal) here: http://www.sfwinecomp.com/pdfs/Result...