Your 3 must have signings at beginning of each save..

totally dependant what club i am - bigger teams i do try and get kadlec or funes mori or both, juhasz, kevin or enyeama if i need them, depends on budgets too. leigh griffiths for any team thats not a top side.
for free players definately nathan rooney, ismael fofana and devann yao
for prem teams this time round was babacar, kevin and sakho
for top teams Neymar, Peter Masilela & meh

LLM I it depends on were I'm at.
So far, I have only started without trasfer funds in first window, but I always sign a couple of frees:

(1) Alexandre N'Gadi
(2) Gauthier Mahoto
(3) Marko Livaja​
M Schelotto ( Cesana) , C Kouyate ( Anderlecht) V Kadlec or Y Sanogo ( whichever I can get cheapest ) all quality players
1. Vaclav Kadlec ---- you can tell why just look at the pic
2. Vincent Enyeama
3. ??? (If i'm, a big club then Yaya Sanogo or Khouma Babacar)
if im a top tier team then it tends to be
1. Bony
2. Mate Simao
3. Jozy Altidore
I dont't have any players I sign on every save. A few I have signed on a couple of occasions though, such as Santa Cruz.
Who's Kevin?

This time around i went for 3 young french guys

1, Clement Grenier
2, Cedric Bakambau
3, Atila Turan

Grenier is an awesome young AM i got from Lyon. he cost me £5.5M which is a steal for what he will become.