Trilian is big and it's much more than a bass guitar synth. It's got tonnes of other basses. Reading this
http://www.spectrasonics.net/products/trilian.php gives a sense of it's enormity - typical Spectrasonics. What do you like it about it? Err... everything! Overkill though if you just want a bass guitar.
Best deal they did was Trilogy with upgrade to Trilian. Two great packages in one for less than Trilian sells for now.
Trilogy is smaller and less CPU intensive so is good for the ideas stage. I don't see it for sale secondhand that often and Spectrasonics have a transfer policy that's so slow it came a distant third behind the tortoise and the hare.
The classic that comes with Kontakt sounds really goood and is used by many.
I still have my Broomstick bass - takes us back to a simpler time when there was less choice.
http://www.bornemark.se/bb/index.htm