Here's are 10 of my recommendations and also among of my top 50 anime theme favorites of all time
*link below the anime music theme songs are the one's who song the theme*
0) Borutesu V Faibu no uta by Horie Mmitsuko - opening theme of Voltes V 1977
1) Daydream Generation by Matsuko Mawatari - ending 5 of Yuyu Hakusho 1992
2) My Friend by Zard - ending 4 of Slam Dunk 1993
3) Ai ha Kurayami no Naka de by Zard - opening 22 of Detective Conan 1996
4) Purachina by Maaya Sakamoto - opening 3 of Card Captor Sakura 1998
5) Sore Ga Ai Deshou by Shimokawa Mikuni - opening theme of FMP:Fumoffu 2003
6) Sakura Kiss by Chieko Kawabe - opening theme of Ouran H.S. Host Club 2006
7) Colors by FLOW - opening 1 of Code Geass 2006
8) Sorairo Days by Shoko Nakagawa - opening theme of Gurren Lagann 2007
9) Triangular by Maaya Sakamoto - opening 1 of Macross Frontier 2008