It depends on your needs. Have you explored SalesForce or Infusionsoft?

There are many solutions out there. The most popular one is Salesforce.com
Other options include Zoho, SugarCRM & Infusionsoft. I know that Salesforce has a great API that many other software solutions are able to connect to.

Hope this helps.

Based on my experience I would recommend Salesforce , it has an intuitive user interface with an attractive design. It also offers excellent reporting functionality and is extremely flexible.

Pretty to look at? I can't help you with that.

I can tell you what tools are easy-to-use -- and completely bad-ass. Take a look at Contactually. It isn't the prettiest, but it is easily the most awesomest platform for keeping track of leads and sales data.

Check it out.

If you're using OS X and don't want to rely on app on the Web, consider the latest version of Daylite. I don't like that it requires a server in order to sync to multiple users and iOS devices, but it stands alone in desktop apps for versatility and the latest version is quite attractive. It's not cheap, but it has no ongoing expense.

Check out Close.io - http://close.io/

Close.io is a streamlined sales platform that helps you close more deals by automatically tracking all your sales communication (calls & emails) without manual data entry.

I've been running sales and marketing operations at companies ranging from $50,000 a month to $100m a year in revenue and have seen my fair share of crms.

None of them are "pretty" out of the box, and what you can do with them generally depends on who you have running them. Some are more limited than others and some are more expensive.

The smartest thing you could do in your situation is connect with an expert to better understand your situation and to pick the system which best suits your needs. Even if the conversation isn't cheap, it will be a whole lot cheaper than migrating after you choose a system that doesn't meet your needs.

As an exercise you should try to brainstorm all the things you want your crm to do for you...

Then connect with an expert, show them your list and ask what they think is missing.

Once you've done that, one last call and ask for help choosing the solution that fits your situation.

It'll cost you $500, and it'll take you a week but it can save you a fortune in time and money if it saves you from making the wrong decision and only realizing it after 6 months

I'd recommend checking out https://www.pipedrive.com - great drag and drop pipeline view (no affiliate or relationship with the company).

You also may consider vTiger. It has very good features right up front. If customization is needed, it can be easily done. For example, we have had clients hire us to write some complex CRM for their "unique needs", but we were able to program and add modules to vTiger for a fraction of the cost that it save them a ton of money. Hope that helps.