F8V

There is no F8V dagger, but HD 27808 appears to be suitable, but its a bit blue.
Hipparcos <B-V>(F8V) = 0.544

MK43 lists 36 UMa as their F8V standard.

Skiff08 flags one star as a F8V MK standard: HD 27808 (MK78). 
MorganAbt73 lists HD 27808 as their F8V fundamental standard. 
Morgan65 classified 4 F8V Hyads: HD 27383, 28033, 28034, 28205.
Garrison72, Cowley74, and Cowley76 used Ups And as their F8V standard. 
Corbally86 used the Hyad Cl Melotte 25 29 as their F8V standard. 

Gray01/03/06 list 50 nearby F8V stars. Median HIP colors:
<B-V>(F8V) = 0.530 (+-0.003 sem, +-0.020 stdev; N=50)
<V-I>(F8V> = 0.601 (+-0.004 sem, +-0.028 stdev; N=50)

# No Standard
Morgan65 does not list an F8V standard.
Houk does not list a F8V standard (she reclassifies the JM53 F8V standard Beta
Vir as a F9V).

# Primary Standard
HD 27808 = HIP 20557 = Cl Melotte 25 48 (only "+" in Skiff catalog)
  F8V: MK73,MorganAbt73,MK78,Jaschek78,Keenan85,Garcia89,Gray89,Gray01,GrayNstars,GrayAtlas
  B-V(HIP)=0.518, Vmag=7.13, Mv=4.07, dMv=+0.14, par=24.5+-1.4 mas

# Secondary Standard
HD 90839 = 36 UMa (J1030+5558; V=4.8)
  F8V: MK43(stan),JM53,Jaschek64(all; 23 refs),Cowley76,Gray03
  F6V: Moore50
  F5: Cannon
  Not a standard in Garcia89, but it is a standard in MK43. 
  Binary w/K7V companion 122.8" away. 
  Excellent agreement on F8V, presumably due to appearance in MK43 & JM53,
  but Gray03 agrees with F8V. Better agreement on F8V than 

# Weak Standards
HD 102870 = bet Vir = HR 4540 = HIP 57757
  F9V: MK73,Garcia89,Kennedy83,Houk99,HoukStandard
  F8V: MK43,Morgan53,Cowley76(stan)
  F8IV-V: Gray01
  B-V(HIP)=0.518, Vmag=3.59, Mv=3.40, dMv=-0.53, par=91.7+-0.9 mas

HD 9826 = ups And = 50 And = HIP 7513 = HR 458 = GJ 61
  F7V: JM53
  F8IV: MK43
  F8V: Garrison72(stan),Cowley74(stan),Hoffleit91,Gray01
  F9Va: Barry70
  B-V(HIP)=0.536, Vmag=4.10, Mv=3.45, dMv=-0.59, par=74.3+-0.5 mas
  Ranges from F7-F9 in the literature. Too much disagreement. 

HD 27383 = 55 Tau = HIP 20215 = Cl Melotte 25 29 (Hyad)
  F9V: MK73,MorganAbt73,Jaschek74,Jaschek78,Abt85,Garcia89,Gray89
  F8V: Corbally86(stan),Gray01
  This star was "the" F9V standard in Gray89, but he calls it "F8V" in 2001.
  It appears to be much bluer than other F9Vs in Houk. Arg!
  B-V(HIP)=0.509, Vmag=6.85, Mv=3.68, dMv=-0.18, par=23.3+-2.3 mas