In 2005, myself and a team of mortgage bankers, beta tested "Salesforce.com" I have been a believer since introduction.
I have had experience with ACT, Salesforce, Splendid CRM, and Microsoft Dynamics via Ledgeview Partners. I agree with the comments about Salesforce being very powerful, but geared towards the likes of a Chevron (which was using Salesfore in 2012). Microsoft Dynamics is a powerful tool, worth looking into.
s a Vice President and Financial Advisor for almost 16 years (having workerd for Prudential Securities, Morgan Staley and Merrill Lynch) I started out back in 1996 using ACT and Goldmine. The product came in the form of software which need to be loaded onto my computer's hard drive. It allowed you to customize screans by adding and/or deleting fields, etc.
Now I use and swear by SalesForce or SalesGenie. However, it all depends on what you need and using the CRM for. In my case currently, I am a business consultant and only a year into this new industry for me (having changed careers in 2012). So one of my needs is being able to prospect for new business. SalesGenie is an excellent tool for generating filtered lead lists. The CRM portion of it is okay at best. With that being said, SalesForce is top notch. Again, you have the capability of altering screen layouts, fields, etc. You can run a host of reports. For example, I can run a report which shows me the number of business proposals I presented and the number of deals I closed/won. These reports can help you identify areas of presonal strengths and weaknesses.
I think a lot of it depends on your size, sales staff and amount of money you'd want to spend on a CRM solution.
Salesforce is a great solution. The api is easily integrated into any piece of software you currently use. But, it can get very pricey.
Like Tom said, Zoho has a nice suite of products too.
If you're looking for a very light-weight, inexpensive solution, I've heard good things about OnePage and Sugar.
I believe Zoho is a great platform for small to medium size businesses and for large businesses I recommend Salesforce.com