Well, Mr. Darcy's extremely awkward proposal really caused a lot of effects on Elizabeth. First of all, he comes into her room presumably to talk just about anything, then they get into an argument, he insults her family, her upbringing, her behavior, you name it. Right there, in the middle of it all, he tells her that he loves her passionately.
At this point Elizabeth has seen how he admitted that he told his friend not to propose to Elizabeth's sister, she also still believes that Darcy took away a fortune from Wickham AND now he comes and spills his guts against her social status? Just imagine: What would YOU have done?
Well, what Elizabeth did was basically to say that nothing in the would would entice her to even consider his proposal, and some other less mild "pleasantries". To this effect, Darcy left angrily, swore he'll never propose again, but when he left he wrote her a long letter at least explaining how he was innocent from the Wickham issue.
Bingley and Jane were so plain and bland in the story that it is easy to forget their proposal. It is known that it was supposed to have taken place during the Netherfield Ball, and that it was because of Darcy that it never took place. We also know that they had tried to stick Georgiana Darcy (Darcy's sister) up Bingley's heart so he could forget Jane. However, after a man to man talk and a big "sorry" from Darcy, Bingley finally acted on his own accord, went towards Jane, and proposed to her.
As bland as their characters were,you can imagine the effect on Mrs. Bennet, who was in high heavens with both future marriages (money and power make good husbands), but Jane and Bingley themselves were just in bliss, and not really sharing much. All the"meat of the matter" lays in Elizabeth and Darcy.
I have edited this question to refer to one proposal as you are only allowed to ask ONE question according to enotes regulations. I will focus therefore on the proposal of Mr. Collins, analysing it and also its impact on Elizabeth.
The proposal of Mr. Collins to Elizabeth comes in Chapter 19 of the novel and is a typical example of his stupidity and lack of imagination. He explains it is his religious duty as a vicar to marry and above all that Lady Catherine de Burgh has recommended that he do so. A marriage to Elizabeth would help heal the breach between their families and also provide for Elizabeth's mother and sisters in the event of her father's death. Generously (note the irony here) he is willing to ignore Elizabeth's lack of money that she can bring to a marriage. Despite Elizabeth's refusals, Mr. Collins insists on believing that this is an example of her modesty or flirtatiousness, in keeping with the behaviour of "elegant females".
Humour abounds in this proposal. The speech of Mr. Collins is stilted, pompous and focused on an overbearing egotism. His wordy method of discourse leads him to structure his proposal as if it were a business plan ("firstly... secondly... thirdly...") which is hardly suitable for a declaration of love. Throughout his proposal he is so sure of his many merits and virtues that he has not considered Elizabeth's feelings or the possibility that she might refuse him. There is a note of tremendous irony when he says: "But before I am run away with my feelings on this subject..." There is no character more unlikely to run away with their feelings in the novel! His reference to Elizabeth's low expectations and financial situation is indelicate at best and is perfectly in keeping with his arrogance and belief in his own self worth.
However, often with Austen, humour masks or accompanies serious social realities, and these are again unsympathetically made very clear by Mr. Collins:
...and you should take it into farther consideration that in spite of your manifold attractions, it is by no means certain that another offer of marriage may ever be made to you.
Thus the economic realities of wedlock appear in their most unattractive light, and Lizzie is forced to confront the reality that by denying Mr. Collins and holding out for a marriage of love, she may never marry at all. This foreshadows Charlotte's acceptance of Mr. Collins for security and a position. Thus although it is an excellent piece of comedy, it also serves a more important purpose in the text.