Question: what are the most collectible stamps?
Answer: Two Penny Blue. ...  Baden 9 Kreuzer Error. ...  1918 Inverted Jenny. Value: $1.593 million. ...  The Whole Country is Red. Value: $2 million. ...  Mauritius Post Office Stamps. Value: $3.8 million for a pair. ...  1859 Sicilian Error of Color. Value: $2.6 million. ...  Treskilling Yellow. Value: $2.3 million. ...  British Guiana 1 Cent Magenta. Value: $9.48 million.