My husband and I went here for Christmas dinner. The wait was going to be 50 minutes so we headed to the bar and spotted an empty two top in the bar section so we asked to be seated there instead. They said OK but were very up front about how busy they were and that service would be slow. We didn't mind since we didn't have plans for after dinner yet.
We ordered the chicken satay with spicy peanut sauce - yum. Next up, we ordered the yellow curry (suggested by the very friendly bartender) and the husband got something with seafood I think. We asked for 8's because we love our Thai food spicy and what we got... was nothing short of amazing. I'm telling you that i've been to Thailand and had their curries... This is on par with the authentic cuisine.
The prices weren't terrible considering you're in Vegas and the ambience was beautiful -- white thick rope tying everything up and dark wood everywhere.
If you like Thai food, don't like being ripped off for subpar food and you're a foodie that doesn't mind waiting a bit between courses, Lemongrass is your perfect Vegas dinner spot.