Kiva and OOO's. It's been too long since we had Riders that can sing. Last time it was Drive (Spinning Wheel).

Faiz and Kabuto have some of my favourites, despite being two of my least favourite shows.

Black/Black RX are forever the grand champ/s of soundtracks. But for some others, I tend to listen to the songs from Agito-Kabuto a lot.

For me its the original Kamen Rider. I often play Let's go Rider kick at work while my co-workers either look at me in confusion, ask about the song or sing along (horribly).

I also agree with Black and RX being awesome and apparently so does most of the males in our workplace. ( Black and RX were a big part of our childhood)

Kiva, OOO and Gaim. I miss the days when the actual actors sung their Insert Songs, they came off much more personal that way, and majority of them end up the best of the franchise.
I'm not a fan of when they have to rely on Rider Chips & Rider Girls all the time....They're hit-or-miss with me. The Girls did their best work in Wizard tho, I'll give them that.

Personally, I'm a big fan of Gaim, with Ranbu Escalation being possibly my favourite Rider Song of all time, but I have to give props to Den-O and the infinite variations on Double Action, as well as Real Action and Action Zero. Kiva comes close, probabably in a 3rd place. Drive could probably switch with Kiva on a day where I listen to Spinning Wheel, so lets put that 4th. And Ex-Aid has Wish in the Dark, so that's 5.

Fourze and Gaim had a lot of personal favorites.

I mean Fourze had Giant Step, Cosmic Mind, Bounce Back, Saite, if we count movie themes there's Voyagers which I freakin love.

Then there's Gaim, Raise Up Your Flag, Ranbu Escalation, Toki no Hana, Never Surrender, then the 3 Gaim Gaiden themes which are all just so good.