Something drier and a bit "saltier" are manzanillas - I would recommend something like Hildalgo
Amontillados are dry and "nuttier" - Gonzalez Byass is a good one
Oloroso (literally "scented") are just that - Gonzalez Byass is another one to look for
Fino are light and dry, probably the most neutral of all of them - Tio Pepe from Gonzalez Byass is a good start.
Stay away from Creams (like Harvey's). Usually, for just about $5 more that the cheapest stuff you can find something pretty nice. I like sherry with almonds and olives as an aperitif.
Thanks for the info, I have a lot to learn in this area. Mine and the wife's experience is limited to the cream types, last night she was drinking some Sandeman Armada Cream Oloroso. She seemed to like it, but its not to my taste at all. We will have to investigate some of the other options.
Picked up a bottle of Dry Sack and a bottle of Lustau Pedro Ximenez San Emilio to try. It may be a day or two before we have a chance to sample these, but will report back with our impressions.