I took part in a discussion with some startup founders in SF via email, and we were trying to figure out the best set of tools to manage the business side of customer development, support and all that jazz. Roy Rodenstein, an angel investor and founder of Going.com (acq. by AOL) had asked that I post my answer in the form of a blog post, so here goes:
37 Signal's Highrise should be the center of any awesome system. Their super easy integrations to so many other services mean information across your business is synced, which, when it comes to a lot of it, is a lifesaver.
I love Highrise's "dropbox," which allows you to cc their system on any important emails. I do this when my email exchange with someone is meaningful either because they provided some wicked feedback or they had a really interesting thought on our company. You never know when you'll revisit what they had to say.
You can really easily integrate Snap Engage or Olark into Highrise, then all inbound support chats are automatically assigned a contact in your CRM. So I'll be working, get a live chat request sent to me via gchat and can later follow up with that individual because most of their information is automatically synced.
Zendesk is a great app with an easy integration into Highrise as well. Enough said.
When you run an email campaign, just integrate Mail Chimp into Highrise via the tags you use and bam, the CRM will track all the interesting stats about that campaign.
My heart is with Wufoo, which has a great integration into HR as well. All contacts automatically become synced, and you can watch them float across your Highrise newsfeed in real time. Pretty sweet!