You use imaginable after a superlative such as "best" or "worst" to emphasize that something is extreme in some way. 可想像的 (常与)(best)(、)(worst)(等形容词最高级连用表示强调)
adjective [原级]可能的;可想象的
The house has the most spectacular views imaginable. 从这所房子可以看到所能想象的最壮丽的景色。