...can be pretty awful.
So I threw myself under (well, at least in front of) the bus for you and tried a few of the less expensive examples.
2008 Maipe Chakana - my first Argentine example (see, I don't hold a grudge over the Falklands!). Soft and pleasant, nothing paticular in terms of structure.
2007 Gascon '1884' Reservado Malbec - different story here - I quite enjoyed this one. Spicy nose and end, decent but not too sweet or overblown fruit in the middle. I'd buy this again. I intend to try their Syrah soon.
2005 Baldes Cailloux de Rieu - a Cahors wine, and as expected it was in a leaner less fruit forward style, pleasant with good mouth feel, but nothing out of the ordinary. Serviceable wine.
2004 Alain Perrin Pourpre de Grezette - as per the name, a big purple fruit forward wine, with well integrated tannins. Great to pop with a steak or just because you feel like a glass of wine.
Winners - the Gascon and the Pourpre - both well worth trying, and both c. $15 Can.