There are many tools out there. Which I guess is a good thing. But how to find the best for your business?
One tool that I started using on my iPad is called My Sales Opportunties.
I liked its simplicity and easy of tracking and managing my sales. And the price ($8). :)
And there are million of web based CRMs. Most popular are SalesForce.com, vTiger, Sugar CRM. They all cost from $20-$50 dollars per user per month.
What I would suggest you do it first define what are top 5 things you want to achieve by implementing your new CRM. And start from there. Look art which software will give you this in an easy and simple way at the least cost.
Do not forget, sales people do not like CRMs. This is because they see it as a 'big brother' controlling them. So if you find the way for reps to like your CRM you got the winning ticket.
Sorry for not giving you a simple answer, but this is not an easy question.
But look for tool simplicity, how to get reps to like it and at the end the price.