I think Lara and Tendulkar are lightyears ahead of the rest.
The effect these two had on cricket is enourmous, they were the shining lights of their countries sides for years and carried the hope of a nation(in the Widnies case, a small one) where ever they played.
Lara was/is a genius, capable of playing superb innings under pressure and knotching up giagantic scores, he averages 52 against the strongest bowling line-up in world cricket and would have as many centuries as Sachin if doubles counted(of which he has 8,Sachin 4).
Admitedly, he isn't the most consistent player over a series, but his overal record speaks for itself, especialy as he's carried the worst Windies line-up for years.
Sachin has been playing international cricket since he was 16, and has had to put up with
un-precidented amounts of media pressure. He is capable of destroying top class bowling attacks and does not have a bad record against any country(i think, haven't checked the stats) he has been amazingly consistent in both forms of the game for someone who's been playing international cricket for 16 years. He was a national hero and just looks a million miles beter than anyone when he's playing well. Ok, you may point to the fact that he hasn't scored as many noticeable innings as Lara, but the amount of runs/centuries he has scored are just as valuable.
These two are both legends of the game, and i think atm they deserve to be head and shoulders above the rest.
Out of the others, i think Ponting is a clear 3rd. He is well placed to break a lot of records set by Lara/Sachin and the form he's been on of late has been outstanding. The only real reason i rate Lara and Tendy higher than him is because he hasn't finished his career so it would be un-fair to rate him totaly when he could still get better.
Dravidand Kallis are both terrific players, but in my opinion they bat too slowly and don't have the same match winning ability as the other 3. When their careers are finsihed, i don't think they will have the same status as Lara and Sachin because there will always be the question of batting too 'selfishly' (not that i think they do). This may be unfair because they are still fantastic players but i won't speak to my grand children in the same manner about these two than i will about Lara/Sachin/Ponting.
Inzy is also a great player, and does fantasticaly well in tight situations but i think he has had too many bad patches to be considered in the same bracket as the others.