This might not be the type of answer that you're looking for but the issue that has most affected me (running a one-person nonprofit from home) is that I've occasionally had problems because my IP address is shared by "adult" web services because I do not have a dedicated server or address.
And so . . . with my nonprofit's focus on the prevention of teen dating violence I have people in school districts regularly contacting me via email and/or visiting my website from schools. From time to time my IP address used to wind up on block lists and I would spend a fair amount of time contacting school web admins to allow my emails through and/or access to my site.
The host I use (HostGator) has worked well for me but unfortunately does not offer a shared-but-not-with-any-adult-sites hosting plan. What I've done to ameliorate the impact is: (1) use Google's fantastic (and FREE) support for nonprofits by using the free Google Apps service to route all of my email accounts through Google and (2) use a free service to monitor my inclusion on any blacklists (MxWatch Monitor via MxToolbox.com). As a result I've been able to avoid almost all email issues and have been able to address any other blacklisting issues as soon as they crop up.
I don't have the web traffic that you do (approx 5,000 unique visitors daily and less than 50GB monthly bandwidth) but HostGator has been almost completely hassle-free. This is the third hosting company that I've used in the past 7 years and I doubt I'll ever have to switch again. I pay around $20 / month and that includes reseller hosting (I help out a few other sites for small nonprofits that don't have a tech background by hosting their sites for them).
If you need further info feel free to contact me - and if you decide on HostGator I'd be happy to give you a referral code (my org could use any and all financial support possible!!!).