Projector

I can say that my LCD does not look nearly as good as my brothers DLP.
150 inch is a huge stretch for any projector. I wouldn't believe anyone's claims of an LCD handling this with quality unless you see it in person.
I bought my LCD when I saw the same model in a club playing on 15 foot screens. I'd never use it that large.
The other issue to consider is where will the unit be located. Many units have built in fans. You really don't want a fan above your head.
You really need to see the exact player on the exact screen to be satisfied. The source can be a huge difference too. The last thing you want is to spend $2500 and have a fuzzy screen...

How about saving some money on the screen by using a white bed sheet and glue the sheet to the wall. Next, go to home depot and buy some cheap wood to make the frame around the white sheet. Last, paint the wood frame to black.

Estimating cost: $30.00

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Get a projector. Bigger is better if you have the space for it. If you are able to darken the room sufficiently, the projector will best a television every time. Sure, the television with its smaller screen may be sharper, but the huge image of the projection screen more than compensates. A 40 inch flat screen monitor is probably sharper than your local cineplex.....but the cineplex with its huge screen wins every time because of its sheer size. Bigger is better and you'll never go small again. Remember, the whole idea of home theater is to emulate a comercial theater if you have the room to do it...
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Mitch,

You may have mislead OP with your bigger is better comment. It's not just a space consideration. It's the ability of a projector to throw an adequate picture on a large screen, an ability unlikely on a 150" screen for any projector even thousands of dollars above OP's price range. OP needs to adjust his expectations, and "bigger is better" is not part of that adjustment.

db