My choice of tyres for any car (budget permitting) is Michelin. I have recently fitted these on my 2.6 Elite, and they balanced up with no issues with very few weights at all. Our tyre fitter at work says anything can be balanced, but generally the better quality the tyre, the easier it is to balance with less weights.
As DG says, a lot depends on the tyre fitters experience. I have seen fitters stick weight after weight on a wheel in the hope of getting it to zero, when an experienced fitter can remove just one weight, re-position it slightly, and the wheel balance comes back at zero.
Another point many tyre fitter overlook / ignore are the tyres sidewall colour markings. Many new tyres have a red or yellow dot on the sidewall. This denotes the heavy or lightest part of the tyre (can't remember which), and this dot is supposed to be positioned adjacent to, or opposite the valve, for optimum balancing with the fewest weights.
Most balancing machines now have a laser and a weight positioning arm that ensures that the weights are positioned exactly where they are supposed to be, rather than the old 'hit and miss' method of rotating the rim to the upright position and then physically sticking the weight where the fitter thinks is the top. This works 99 times out of a 100 but, is prone to errors.
In extreme cases when there are balancing issues, the only alternative is 'forced wheel balancing'. This is not available at all tyre places. It consists of a large drum that exerts force on rotating wheel and tyre, and establishes the heaviest / lightest part of the tyre and rim. The tyre bead is broken and the tyre is rotated on the rim to the optimum position indicated by the forced balancing machine, and then balanced in the normal way.
This costs a bit more, but for problematic wheels, is a viable alternative.