I love Castlevania.

But Metroid has been way better to me.

From what I've played, I'd have to say Metroid.

Symphony of the Night is one of the best games ever made

Loved Super Metroid, but Symphony of the Night is one of the best games ever made and Castlevania, as a franchise, is a personal favorite. So that's where my money goes.

I have only actually played Super Metroid and Castlevania II, but I can still form an opinion out of everything I know.

1. Metroid, I know that Castlevania is heavy on the RPG elements, something I probably won't really care for in a Metroidvania-style game.

2. Super Metroid, the only one of those two that I've played.

3. Guacamelee (more specifically STCE) is incredible. I enjoyed it immensely.

You know my answer

For me it started with SotN, but in all honesty I probably like Metroid more as it is far more accessible IMO. Other titles. Well as you mentioned Guacamelee was fun, and A:I was also one damn cool title. And Shadow Complex was pretty damn cool as well, but that to was already mentioned

Castlevania sotn is tied in my top three games ever soo. Duke nukem... jk

1. Castlevania.
2. Super Metroid.
3. I'm pretty sure I've only played Castlevania 1 and a few Metroids from this genre... so let's say Zero Mission.

Castlevania has (had?) the potential of being a lot better than it is, and I would like it more than Metroid if it followed it's roots from the original games more (complex level design, pain in the ass difficulty, slow pace, tight controls) but it didnt, meanwhile Metroid did and made a beatiful masterpiece in gaming history.

I should get Castlevania 3...

1. Castlevania, no doubt about it.

2. Super Metroid, Symphony of the night is not the best in the series.

3. Guacamelee.