Well let's see, a quick top 10 would be:
10
Makafushigi Adobencha! (Mystical Adventure!) [DB opening theme]
9
Hitori Janai [GT first closing theme]
8
Dan Dan Kokoro Hikareteku [GT opening theme]
7
Don't You See! [GT second closing theme]
6
Sabitsuita Machine Gun de Ima o Uchinuko [GT fourth closing theme]
5
Unmei no Hi ~ Tamashii tai Tamashii ~ [DBZ Super Saiyajin 2 Gohan insert]
4
Cha-La Head-Cha-La [DBZ first opening theme]
|
3
Bokutachi wa Tenshi datta (We Were Angels) [DBZ second closing theme]
2
Blue Velvet [GT third closing theme]
1
Mind Power ... Ki ... [DBZ Mirai Trunks flashback insert]
1, 2 and 3 are pretty much on equal footing, but ranked them anyway for the sake of a list. And We Gotta Power would be at 10 if DB wasn't considered.
I consider mostly the melody, specific image triggers (of parts of the anime) and overall impression, rather than mostly lyrics like many people do.
Oh and this is coming from a fan of alternative rock, Cantonese and Mandarin pop, and Japanese rock. So it would I mean that a catchy rhythm, an upbeat melody and significant loudness would often get my attention.

The analytical enigma. 分析性的不解之谜.