Glo500naira for 3GB night plan 12-5am valid 7days and on weekends... It's really cool...they even monitor it for you... I've downloaded a lot from this thing.... Airtels 50naira for 1.5GB is cool tho but the speed isn't as good as Glo here... And I'm gonna try and see if I can do double... Ie 1k for 6GB maybe it will work and they might give me 14days.... 

You guys can try Etisalat 500naira fr 500mb valid 30days

airtel 1k for 3GB BB complete plan on Android (tweak IMEI to that of a bb10 to work)
Or 1500naira for the same 3GB that works on all devices (your choice)
Airtels 500naira for 750mb valid 14days(all users) or 500naira for 1GB valid for 7days(smart trybe users only)

These are the plans ive tested and confirmed Sha... None of them passes 2k ... Looking for cheaper ways of going online... Still testing... Let me know if you've found something else that's cheap and good