I have used a the following omni's:
AT853 omni's loved them....these were the older version.
MBHO Omnis..loved these as well...still have them a tad bright but I like a little crispiness.
RODE NT2000 these would bass you face.....they would literally suck every last drop of bass out of the air... I wasn't real crazy about them...always had to roll it off a little.
Senns k6 omni's.....to much high end emphesis which I normally like but I don't like this line of senns.
Avenson STO's....probably my favorite...super linear... these too are bass hogs but in a good way... fabulous up close...treble drops off a little further back...but not much.
DPA 4060's....great mic stealth or open..... haven't made a bad recording yet with these.
A friend uses Neveton's mce400...its one of the best little omnis I have heard....I might like them better then my DPA's but I try and talk myself out of it just so I don't have to buy a set. these recently went up in price.
Same friend uses Gefells...270...these a real nice too...but you need big bucks for these..
All this to tell you my favorite is probably the avenson STO's...
But that could change.....
Good luck in your quest.....mics are like icecream... so many flavors.... all really good if you like the flavor.... if not, its still icecream...
peace OOK