Well, it's a partial list. 28 cars -- but I only went 2/3 of the way through the thread so far.
If the poster included all relevant details plus it was rated 35+ mpg US highway, it's below.
I love the fact that it even includes a few hybrids and a diesel.
Sorted by make:
Chevrolet
Chevrolet Metro, 2000, 1.0, 119000 miles - $950 - EPA: 33 / 41 / 36
Ford
Ford Aspire, 1997, manual, 149480 miles - $1495 - EPA: 29 / 38 / 33
Honda
Honda Civic coupe EX, 1997, 5 speed manual 177000 miles - $1200 - EPA: 28 / 35 / 30
Honda Civic DX, 1993, stick shift - $1100 - EPA: 34 city / 40 highway
Honda Civic EX sedan, 1997, manual, Kilometers 256650 (159k mi) - $995 - EPA: 34 Combined 31 City 39 Highway
Honda Civic Hybrid, 2003, $1300 - EPA: 40/43/41
Honda Civic Hybrid, 2003, manual, dead IMA battery, 294,748 miles - $1100 - EPA: 38 / 45 / 41
Honda Civic sedan, 2001, 5-speed, 400k kms (249k mi.) - $1300 - EPA: 28 / 35 / 31
Honda Civic VX, 1994, 294xxx miles - $1500 - EPA: 39 / 50 / 43
Honda Civic, 1996, 5spd 120K miles - $1500 - 35MPG HWY
Honda Civic, 2004, 5 speed, 262k km / 163k mi - $1500 - EPA: 31 city / 39 highway / 34 combined
Honda Civic, hatchbach 1994, 5 speed 190000 miles - $1150 - 33 / 41 / 36
Nissan
Nissan 200SX, 1997, 128000 miles, manual - $600 - epa of 35 highway
Nissan 200SX, 1997, 5 Speed Manual EPA: 25/29/35 if it has the 1.6L.
Nissan Sentra, 1999 5spd, 156k milest - $750obo - EPA: 25/35/29 if it has the 1.6L
Saturn
Saturn SL1, 1996, 5-speed, 180K miles - $1250 - EPA 25/36 (29) or 22/32 (26)
Saturn SL1, 2000 - $1400 - EPA: 25/29/36
Saturn SL1, 2002, Manual - $1100 - EPA: 25/29/36
Suzuki
Suzuki Swift, 1998, 1.3L, 5-speed with 60,000 km (~40k mi.), $900 - EPA: 31 / 38 / 34
Suzuki Swift, 2000, 1.3L, manual, 320k km (200 mi) - $900 - EPA: 31 city / 38 hwy / 34 combined
Toyota
Toyota Corolla, 2002, Manual , Kilometers 276000 (171k mi) - $1500 - EPA: City 28 / Highway 37
Toyota Echo, 2000, 1.5L, 5-speed 200,000 km (120k miles) $1000 - EPA: 29 / 37 / 32
Toyota Echo, 2001, Manual , 250000 km (155k mi.) - $1000 - EPA: 29 city / 37 hwy / 32 combined
Toyota Echo, 2001, automatic, 210k miles - $700 Obo - EPA: 30/35/27
Toyota Prius hybrid, 2001, Kilometers 190000 (118k mi.) - $1500 - EPA: 42 City 41 Highway
Toyota Prius hybrid, 2002, 190k miles - $1400 obo - EPA: 41 mpg hwy
VW
Volkswagen Jetta TD, 1999, Manual, 145000 (91k miles) $1200 - EPA: 33 / 44 / 37