Should I fight or is it time to go?

I'm 23 and my boyfriend is 25. We've been dating for a 1 1/2, but we've known each other for 3. We enjoy a lot of the same things and we share the same group of friends (which is how we met). In the beginning things were going great. We hung out almost every night, even though he had work and I had school the next day, and we always called and texted each other. Jump ahead 6 months, after the "honeymoon phase", and things are not always so happy.

I feel like I have to fight for his attention. Most of the time, almost always, when I call or text him I receive no reply. I'm the one asking to hang out or setting up dates. I can't remember the last time he said, "would you like to go out tonight," or "would you like to come over?" And when we do sometimes he doesn't show or is late and he blames it on work. Granted he has a demanding job, but I feel like he needs to have a proper balance of work life and social life. He seems to have time for everyone else. Why not me? I feel like a third-wheel in his life or a buddy, not a girlfriend and I've said this. He also enjoys making me the butt of every joke.

But when we're together things are different. He doesn't make fun of me (as much, it's more playful), he's romantic and the butterflies in my stomach come back 10 fold. But when I tell him how I feel about being ignored his reply always is, "sorry, I was busy," , "I had an important work call," or "I left my phone somewhere." That excuse, to me, only gets you so far for so long.

I guess what I'm asking is, should I stay? I have cried over feeling this way many times. His best friend has confessed to me that he wonders why I stay. I know he loves me, he shows it in his own little ways, but...I don't know.

I'm a firm believe in fighting for what you want and I want him. But I also believe that you can only beat a dead horse for so long. Is it time to stop beating the horse?