EzekielRaiden
Follower of the Way
Frankly I don't entirely get the case for bless here.I picked haste, but I always play frontliners.
All three would be sweet, though. On anyone.
Front-liners love the movement opportunities and many appreciate the extra attack from haste, especially non-Fighters who get various ways to make fewer but stronger attacks (the extra dice of damage of Improved Divine Smite or Sneak Attack, static damage from Thirsting Blade, spells that tack on bonus damage on melee hits, etc.) Unless you know you're going to be rolling lots of dangerous saves, it seems to me that haste grants front-line types more benefit.
Spellcasters love Disengage and get a lot less out of bless due to leaning much more heavily on inflicting saving throws rather than making attack rolls (not that there aren't spells, sometimes good ones, with attack rolls, just that most good spells are save-based.) So again it seems like haste grants more benefit than bless.
And nobody is gonna complain about always having a free chance to quaff a healing potion while still doing your main thing. Oh! And haste still offers defensive benefits due to giving +2 AC, which is always desirable in 5e's math. Getting +2 AC is gonna be a lot more consistently useful overall than getting on average +2.5 to saves!
Haste offers a lesser version of Action Surge...except it's available literally every single round. Bless is a buff, yes. One that goes outside of Advantage/Disadvantage on a small set of prevalent and important rolls (saves and attacks you roll). If bless applied to your saving throw DC as well as to attack rolls you make, then it would be WAY more tempting. As it stands...I really think it's only Fighters and maybe Barbarians who would really benefit from bless more than haste.