Match Group - In this business, size matters, and Match Group operates at significant scale, along with an International footprint.
Meetme - Are essentially a family run business. They sit in the middle ground between dating and social networking. Fallow ground for growth IMHO. Momo has shown a clear path to monetization, and Meetme should be able to copycat their way to profits by modeling their success.
Spark Networks / Affinitas - Spark Networks has been bumbling along for years. Affinitas has the most to gain by buying them. They'll benefit from economies of scale and combining know-how. They'll be able to raise more money, more easily.
I do not make any recommendations in this post. I'm merely expressing my opinion, and putting my money where my mouth is. You can see one-pager summaries on publicly-held Internet dating companies on Online Personals Watch here.