First, thanks Andy for starting such a thought provoking and fun thread (and for helping me formulate my shopping list for 2008 ). I agree completely with your quote as above, and already consider all Diana, BSF, FWB, HW, Webley and BSA rifles from the 1970s/80s & 1990s to be collectable. Therefore, I will try and forecast which air guns from 2000 to the present will become future classics to be collected and coveted, and have come up with the following four (and in each instance recommend .177 ).
1) the last of the old-style walnut stocked Air Arms TX200HC & TX200 rifles from 2006/7 (not the new computer etched stock models which imho just don't cut it);
2) the last of the walnut stocked Longbow rifles to leave the Birmingham manufacturer of Webley & Scott as was from 2005/6 (not the new AGS imported models);
3) the BSA (Gamo) walnut stocked Lightning XLs as are currently available via any air gun shop in Gt.Britain (and beyond ), and finally ...
4) a pre-charged rifle namely the BSA Hornet carbine single shot that was replaced by the Scorpion carbine due to cheaper unit production cost earlier this year.