Assuming you mean the 2008 compilation (released as part of Sony's Playlist series or the European Best Of that includes rarities and hits), here’s a concise review:
For fans seeking the "RAR" (rare) side of the band, the (Double CD) of the Best Of is the gold standard. It features a second disc entirely dedicated to B-sides, demos, and alternate versions that reveal the band's experimental spirit. Notable Rarity Original Source / Context "Pooh Song" B-side from "Sick & Tired" (1994) "Deuce" Featured on The X-Files: The Album "Carnival (Puck Version)" A stripped-back, alternative take "Hold Me" (Mini Version) A short, haunting acoustic piece "Slowdown Town" the cardigans the best of rar hot