The top speedy threats and their Base Speed are:
Ninjask - 160
Electrode - 140
Swellow - 125
Alakazam - 120
Cincinno - 115
Scolipede - 112
Tauros - 110
Durant - 109
Galvantula -108
Scyther - 105
Entei - 100
Yanmega - 95
Moltres - 90
Cresselia - 85
Gallade - 80
Honchkrow - 71
This is off the top of my head so there may be mistakes and a lot of unmentioned Pokemon in there but they're the first things that pop into my head when thinking about threats.
There's also Accelgor (145), Dugtrio (120), Sceptile (120), Zebstrika (116), Persian (115), Sneasel (115), Floatzel (115), Swoobat (114), Serperior (113), Purugly (112), Jumpluff (110), Archeops (110), Liepard (106), Rapidash (105), Lopunny (105), Cryogonal (105), Emolga (103), the Simi's (101), Fearow (100), Raichu (100), Dodrio (100), Miltank (100), Linoone (100), Slaking (100), Regigigas (100), etc. though admittedly few of those are used that much.