Thanks Phil, Jack and Debbie.
Jack, my exotics include Large Tortoiseshell (5; 3 at Woodhouse Copse, 1 at Newtimber Hill and 1 at Littlehampton Bridge), Camberwell Beauty (1 at RSPB Pulborough) and Queen of Spain (9; 8 at Chichester and 1 at Springhead Hill). I don't include the 2 Black-veined Whites at Stockbridge Down, as captive-bred origin was apparently later admitted to a BC Hants & IOW committee member. So no Monarch yet, but this and Long-tailed Blue are my next best targets.
I think it's worthwhile stating that although an element of 'listing' is inevitable once you've seen the Lion's Share of what's on offer, the real joy of butterflying is the enjoyment of all those associated aspects of the British countryside experienced while in their pusuit, the 'sense of place' they often engender, the study of their fascinating behaviour in ever-increasing detail, the sharing of the experience with similar minds and, high on the list for me personally, their conservation. The British countryside without butterflies would no longer be the British countryside.
Debbie, you are at the start of a very exciting journey. I wish I could do it all again, but like all addicts I now need more and more to satisfy my cravings. Your white SPBFs are the sort of butterflies required to give me the same 'fix' I got from seeing my first Adonis Blue

. That said, the first Orange Tip sighting of each spring goes a long way to fulfilling that need.
Neil