By such a wide margin (amongst the tools that our team currently uses or has worked with in the past), RingCentral has to take the cake here. Their chat support is slow, the phone support can lead you to believe that they don't really care about customer retention, and the email responses are slow and often incoherent.
Of course, this is all based on our experiences (and it's possible that we've gotten stuck with a few bad apples), but I've been shocked at the general lack of attention placed on the customer experience by the RingCentral team overall. Granted they are a super cheap option for VOIP services but I want to believe they can do better..
A self-described "light CRM", Notion is an awesome tool for to-do lists and personal life management. I had initially explored the platform as a team-wide collaboration database but found it to be much better suited for external action items. Smooth interface, nice features. Highly recommend.
Our team dabbled between several CRM's (Pipedrive, Zoho, Apto) prior to making the switch to Hubspot, but have really found their all-around tool easier to use. I believe if you're a larger team considering making the move over to Hubspot (say from Salesforce), you may find the limited customization features to be hindering, but for a smaller team just starting out or looking to streamline all client communication in one platform, you'll be very happy with Hubspot. One other thing to keep in mind : Hubspot was designed to be onboarded and customized internally (a cost-saver) vs. Salesforce, a tool that would likely require the help of an implementation specialist (additional cost) to help your team get up and running.
In February 2018, our team made the switch to Hubspot CRM - a tool that we believed would be a fine replacement for our old CRM and would allow us to visualize our contacts, companies, and deals in a super clean interface. The price point was fairly inexpensive at the time (the CRM alone is actually free nowadays, a marketing ploy by Hubspot to reel new customers in) and we felt it would really help the company grow. We quickly fell in love with the all-in-one aspect of the platform and began transitioning more and more of our business process over to the tool: MailChimp was replaced by Hubspot's native marketing hub, Yesware was replaced by Hubspot's sales hub.
Today, we use Hubspot for their CRM, marketing, sales, and service hubs. There may be tools that provide one of these services more efficiently - but having everything under one roof has worked incredibly for us.
From the moment I was introduced to Zapier several years ago, I completely fell in love with the tool (I've even begun using the paid version in my personal life). Today, my team uses Zapier to automate workflows across 15+ apps and relies on more than 40 zaps to streamline our processes and create efficiencies at every turn.
For the countless hours saved and the value gained from these workflows, the $600 price point (professional level, paid annually) seems incredibly low. If you're only looking to dabble with the tool, you can make use of the free version (free forever, not just for a trial period) or the starter plan ($20/$25 per month).