Quality balsamic vinegar for regular use?

Ooh BuonItalia has some really great stuff! Re: aging, that pertains specifically to the DOP designations I mentioned in my second post, which was an attempt at clarification. The DOP ones can be up to several dollars per milliliter, like I just found one online that is $450 for 100mL. In any case, I would say what you have now is a great starting point, get a feel for it and move up price-wise from there if you want to compare. The specific use matters in the case that the vinegar is the central flavor... if you have it in with fresh onions it's not going to make as much of a difference as if it's dressing something blander on its own. That one sounds like a good place to start, good luck!

Thanks everyone for your help! This afternoon I went into Buon Italia at Chelsea Market and they suggested I start with Acetaia Bellei's Aceto Balsamico Di Modena IGP (http://www.bellei.it/cms/it1143-aceto-balsamico-di-modena-bell-silver.asp). I don't believe it's aged (bottle doesn't indicate, and I don't remember rep mentioning) but it does have a distinct sweetness and though I wouldn't describe it as syrupy, it's got some body. I enjoyed it and price point was reasonable ($9). A decent starting point it seems.
@Rebecca - Some of the recipes call for it in vinaigrettes, others in actual cooking w/ heat etc. Today's experiment (sans pancetta): https://food52.com/recipes/13784-corn-salad-with-cilantro-caramelized-onions
I appreciate all the suggestions!
R

I just did a quick read-up on the Italian Wikipedia article for balsamic vinegar, just to clarify: the two top levels have DOP designation, then comes the IGP which doesn't require a lengthy aging process (among other slight differences). I have never personally had a memorable-tasting balsamic vinegar from outside of Modena and would stick to what I said above, noting that "reasonably-priced" does not necessarily translate as "cheapest," although there are some cheap ones out of Modena that aren't half bad for some purposes.

To be honest, what I have found is that for "every day use" really good Spanish sherry vinegars are typically better than off the shelf "balsamico". I like Cepa Vieja, "vinagre de jerez, reserva". Pretty easy to find in NYC, say Dean and DeLuca.

If you have the time and interest, head to Fairway's Olive Oil & Balsamic Vinegar section. They offer tastings, description & suggested uses for each bottle - reasonably priced, above average quality varieties. I would look for one for salad dressing/vegetable and a small finishing (read pricier)bottle and you should be set to go to experiment. By the tasting section, there's usually someone there that you can talk to about and help you select.

In the world of balsamics, there are no guarantees except "Tradizionale" (i.e. expensive and not for cooking). Bottles bearing the "I.G.P." certification are a good place to start but, as Rebecca says, they come in a wide range of qualities and other vinegars, without such designation, could easily best lesser IGP's. Check the label's statement of age and ingredient list.

Hi RashaB-- Any idea what you'd be using it for, primarily? For my general use in vinaigrettes/macerations/etc I try to find a Modena IGP ("Protected Geographical Indication," in English translation) that is not too expensive. The highest quality ones are very expensive, very viscous, and not sold in most stores here, anyway. They taste far better than what I would usually need for a given recipe, especially in quantity. Balsamic reductions are often mimicking the thick consistency of these expensive ones, which are reduced over very long periods of time without heating. Hope some of that helps? I would just go into Fairway or Zabar's or wherever is nearest to you, look to see which are Modena IGP, and pick the most reasonably-priced one of those.