I found the old version of the IFDB top 100 posted here, and it listed the number of ratings that those games had in July of 2015.
Now, almost 2 years later, it’s interesting to see the change in the number of ratings:
Counterfeit Monkey (2012) by Emily Short went from 51 votes to 76 votes, a gain of 25.
Anchorhead (1998) by Michael Gentry went from 230 votes to 268 votes, a gain of 38.
Lost Pig (2007) by Admiral Jota went from 277 votes to 330 votes, a gain of 53.
Worlds Apart (1999) by Suzanne Britton went from 61 votes to 73 votes, a gain of 12.
Violet (2008) by Jeremy Freese went from 223 votes to 262, a gain of 39.
Trinity (1986) by Brian Moriarty went from 62 votes to 71 votes, a gain of 9.
Planetfall (1983) by Steve Meretzky went from 81 votes to 90 votes, a gain of 9.
Hadean Lands (2014) by Andrew Plotkin went from 18 votes to 27 votes, a gain of 9.
Spider and Web (1998) by Andrew Plotkin went from 186 votes to 209 votes, a gain of 23.
The Mulldoon Legacy (1999) by Jon Ingold went from 28 votes to 33 votes, a gain of 5.
Blue Lacuna (2008) by Aaron A. Reed went from 72 votes to 85 votes, a gain of 13.
Photopia (1998) by Adam Cadre went from 373 votes to 416 votes, a gain of 43.
Savoir-Faire (2002) by Emily Short went from 78 votes to 96 votes, a gain of 18.
City of Secrets (2003) by Emily Short went from 75 votes to 81 votes, a gain of 6.
Bronze (2006) by Emily Short went from 152 votes to 187 votes, a gain of 25.
Slouching Towards Bedlam (2003) by Foster & Ravipinto went from 135 votes to 153 votes, a gain of 18.
Metamorphoses (2000) by Emily Short went from 78 votes to 92 votes, a gain of 14/
Coloratura (2013) by Lynnea Glasser went from 43 votes to 61 votes, a gain of 18.
Suveh Nux (2007) by David Fisher went from 136 votes to 157 votes, a gain of 21.
Enchanter (1983) by Marc Blank, Dave Lebling went from 62 votes to 75 votes, a gain of 13.
Flexible Survival (2010) by Nuku Valente went from 20 votes to 26 votes, a gain of 6.
Endless, Nameless (2012) by Adam Cadre went from 22 votes to 34 votes, a gain of 12.
Make It Good (2009) by Jon Ingold went from 51 votes to 59 votes, a gain of 8.
The Hitchhiker’s Guide to the Galaxy (1984) by Douglas Adams and Steve Meretzky went from 130 votes to 152, a gain of 22.
Eric the Unready (1993) by Bob Bates went from 25 votes to 27 votes, a gain of 2.
Babel (1997) by Ian Finley went from 105 votes to 110 votes, a gain of 5.
80 DAYS (2014) by inkle, Meg Jayanth went from 11 votes to 31, a gain of 20.
Mentula Macanus: Apocolocyntosis (2011) by One of the Bruces went from 22 votes to 25 votes, a gain of 3
The Gostak (2001) by Carl Muckenhoupt went from 41 votes to 46 votes, a gain of 5 votes.
Varicella (1999) by Adam Cadre went from 85 votes to 96 votes, a gain of 11.
A Mind Forever Voyaging (1985) by Steve Meretzky went from 70 votes to 76 votes, a gain of 6.
Vespers (2005) by Jason Devlin went from 101 votes to 121 votes, a gain of 20.
Spellbreaker (1985) by Dave Lebling went from 35 votes to 42 votes, a gain of 7.
The Guild of Thieves (1987) by Rob Steggles went from 17 votes to 19 votes, a gain of 2.
With Those We Love Alive (2014) by Porpentine and Brenda Neotenomie went from 28 votes to 52 votes, a gain of 24.
The highest gains over two years belonged to Lost Pig (53 votes), Photopia (44 votes), Violet (39 votes), and Anchorhead (38 votes).
The highest percentage gains belonged to 80 Days with a 181% gain, With Those We Love Alive with 85.7%, Endless Nameless with 54%, Hadean Lands with 50%, and Counterfeit Monkey with 49%. Each of these are the last ‘big’ games by the 5 most popular authors on ifdb in terms of total review count.
The lowest gains were Guild of Thieves and Eric the Unready with 2 votes each, both commercial games by non-Infocom companies from the end of the commercial era.
The lowest percentage gain was 4.7% for Babel, most likely due to the fact that TADS is now harder to play than Inform or Twine.
As a point of comparison, some games new to the list are from 2015, as follows:
-Toby’s Nose by Chandler Groover (2015) 28 ratings
-Brain Guzzlers from Beyond! by Steph Cherrywell (2015) 42 ratings
-Chlorophyll by Steph Cherrywell (2015) 30 ratings
-Birdland by BP Hennessy (2015) 61 ratings
-Midnight. Swordfight. by Chandler Groover (2015) 32 ratings
And from 2016:
-Worldsmith by Interactive Fables 22 ratings
-Superluminal Vagrant Twin by Pacian 33 ratings
-Open Sorcery by Abigail Corfman 32 ratings
-Cactus Blue Motel by Astrid Dalmady 36 ratings
-Foo Foo by Buster Hudson 17 ratings
-Color the Truth by mathbrush 32 ratings
-16 ways to kill a vampire at mcdonalds 32 ratings
So, overall, Birdland had the greatest increase in number of ratings over the last two years, while Cactus Blue Motel had the greatest increase on average (if you divide the older games by 2 to account for two years of ratings). Of course, comparing old games to new games is comparing apples to oranges, due to the initial bump in number of ratings a new game gets.