In reply to Ciderslider:
The black and white tricams are not very strong, something that put me off buying them. I often find tricams too fiddly to place if I'm pushing my grade (say HVS and up) so wouldn't carry them unless I though the rock may be particularly suited to them (and not so suited to cams and nuts). Other than that they are good in winter and as part of a light rack for easier climbs.
The smallest two sizes of Ball nuts can be really good (especially the red one) especially for rock which tends to have thin cracks that may have a tendency not to take nuts at times. Limestone can often form like this.