Won't bother taking too much time, so here it is:
T1 logos: QBF, Astralis, Liquid, Fnatic, Furia, Spirit, Ence, Extremum, Titan, Immortals, IBP, LowLandLions, D13
T2 logos: Mouz, Flash gaming, Virtus Pro, Heroic, North (old one - new one, before they disbanded, deserves T1 for me), EnvyUs, Gambit, SK, TSM, Epsilon, Mad Lions, Order, Recon5, Invictus
T3: C9, Sprout, Havu (Spraut's ''twin brother), G2, NiP (new logo - old one is T2), Faze, Big, Vitality (was thinking Vitality between t2 and t3), Sinners (btw bravo to them for reaching thus far), Dignitas (new logo - old one is t2) , Luminosity, Optic, Valiance, Avangar, Windigo, AGO (somewhat between T2 and T3), EG
T4: OG, SpaceSoldiers, Complexity
So far so good. Won't bother more with t4 or make t5 list - there are thousands of teams like that. I want to point out one thing - Complexitiy, at starting to reach its peek again, should defn change its logo - its really terrible :D :D :D also EG's logo isn't very good... again...
All of the rankings here are my personal preferences. I surely missed many logos, but can't find everything on the internet for 20 minutes. I point out the ones i remember for being amazing and easy to remember =) thank you for your time. Would appreciate if new logos show up in the comments.