+1 on hubspot. They also have nice APIs and their freemium package is very nice. API usage is part of the freemium package. We use it to send leads from our backend system.

I think their premise is that CRMs are a commodity and all the value is in upselling the type of features that they charge for. So making sure the baseline CRM is very good drives sales for that. Either way, it's a decent product.