There are some great ideas in this thread so far - and I won't let the fact that I have failed to complete every group build project I've ever started deter me from suggesting a couple more....
- Cheap Thrills: Any kit of any LSP subject so long as the all-in cost (kit, decals, resin bits, etc) is less than $50 USD (or whatever value is deemed appropriate). Could be an Ebay win, a swap meet find, hobby shop sale, or whatever.
- Clear the Bench (SOD, Stalled prior GB project): Realizing this would probably violate the 25% GB rule - any project that is sitting there begging to be completed, regardless of how old it is, or how far along. Just get 'er done and into the display cabinet!