"I'm thinking of getting a cyclods and I was wondering if it can play gba games without an expansion pack ? (I posted this over here because I already posted this over at the myds website but it's been three hours and no one has replied )"
No slot-1 flash cart can run GBA files. Your best bet is the EZ-Flash 3 in 1, which can be used to run files stored on a slot-1 device. GBAtemp's wiki has a rather large page about how the 3 in 1 works. I won't go into detail because I've never used one myself, but I'm going to order one and a CycloDS Evolution in a few hours. The 3 in 1 is about $30, so it's a real bargain. Definitely worth looking into.
Edit: Rus_A7 made a post:
"Well, I got an EZ Flash 3-in-1 expansion pack, and it's great. It does need third part homebrew to work with anything besides EZ Flash, but it's still the best option for playing GBA games if you already have a slot 1 card."
To clarify, the 3 in 1 doesn't require an EZ-Flash V, but it's the only slot-1 cart officially supported by it. The CycloDS team have apparently added support to the CycloDS Evolution for the 3 in 1's rumble feature and the extra RAM for the Opera Browser. As for the GBA side of things, I have no idea, but I've heard it works quite well.