Yeah, sure. Depending on what you're wearing, it can make an outfit look a lot better. I especially like wearing them with dresses. It gives me more of an hourglass figure, and helps provide some cleavage for the lower-cut ones.
With t-shirts it can look kind of silly. It has to be a really tapered shirt for it to work, or else I get that thing where the bottom part of the shirt is just kind of hanging off my breasts and not touching anything else. I don't think that's a good look.
Just try on outfits both ways, and see what looks better. Sometimes it won't be obvious, but sometimes there will be a definite winner.
Unfortunately for you (and for women wanting perky breasts in general), studies have shown that wearing a bra actually promotes sagging. With the bra doing all the work, the internal support structures of the breast are allowed to atrophy, and eventually become unable to hold up the breast on their own anymore.