In no particular order:
Pre-Parade (Toradora! OP1)
Silky Heart (Toradora! OP2)
Secret Base - Kimi ga Kureta Mono (10 years after Ver.) (AnoHana ED1)
Yowake Umare Kuru Shoujo (Shakugan no Shana ED1)
Bon Bon (Lovely Complex ED2) (underrated song award)
Blue Bird (Bakuman OP1, OP2 - used different verses of the same song)
Hazy (Hanasaku Iroha ED1)
Future Gazer (Toaru Kagaku no Railgun OVA OP1) (...I assume OVAs count?)
Golden Time Lover (Fullmetal Alchemist: Brotherhood OP3)
Period (Fullmetal Alchemist: Brotherhood OP4)
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If you are reading this signature, then you are wasting a great deal of your time.