There are a range of venture capitalists that I like and would work with in a venture. At Alfresco I've been fortunate to work with Robin Vasan (Mayfield) and Kevin Comolli (Accel). I'd happily work with either again. They are entrepreneurial and empathetic. They're also helpful in cracking into a wide range of companies.
One firm with whom I've never formally worked but would engage in a heartbeat is Benchmark Capital. Matt Aslett of The 451 Group gets it exactly right in calling out Benchmark as the secret sauce behind a majority of the industry's successful open-source ventures...and exits:
[Peter] Fenton made his investments in JBoss, Zimbra and XenSource while at Accel. Benchmark also invested in Zimbra, via Kevin Harvey who led the investment in MySQL [and Red Hat]. JBoss, sold to Red Hat for $350m; XenSource, sold to Citrix for $500m; Zimbra, sold to Yahoo for $350m; and MySQL, sold to Sun Microsystems for $1bn. Whether you are a supporter of the current consolidation in open source vendors or not, you've got to hand it to Fenton/Benchmark when it comes to picking winners.
Amen. Kevin Harvey and Peter Fenton are a dream team in open source. I once asked whether the two could effectively work together. Looks like I have my answer.
P.S. Matt (Aslett): Here's a little-known fact. It was actually Benchmark Europe that got John Newton and John Powell together for the first time to start a company called Activiti. When that didn't pan out, the two stayed together to start...Alfresco. Benchmark has its hands in more fruitful open-source companies than maybe even the formal record would show.