I've broken more Line's than any other ski...
If you really want a ski that will last a few seasons, you're going to have to pay for them. Buying a $400 or less park ski won't last you, you're gonna be looking at paying between $500 and $700 for them (that being said, not all expensive park skis are built to last either).
My personal recommendations (skis that I have owned that have lasted at least one season...something I rarely have happen...I skied 3 different Line skis two seasons ago and 2 different K2s last year...well 3, but one was a prototype so I don't count that):
- Rossignol Scratch/S4 - while this is one that I haven't really owned, but my friend who destroys gear just as much as I do does, and they're going on 1.5 seasons now and have no signs of slowing down.
- Liberty LTE - I got the Phil Larose a few season ago (3 or 4)...used them for a season, beat the hell out of them, downgraded them to urban/rail jam skis...used them for almost 2 more seasons...just finally retired them a few days ago when the heel piece started to lift (keep in mind, these spend their time getting beat on and then left lying around with dirt, mud, and water soaking into them, the core doesn't seem rotten, just two stripped holes that I don't feel like dealing with).
- ON3P Filthy Rich - I haven't skied these yet...they're sitting in my closet right now...but I drilled into them when I mounted them and they've got one of the best cores I've ever drilled. The edges look thicker than any edge I've looked at (they almost look unnaturally thick...it's awesome). This is my top pick, usually small companies like this put a lot more attention and detail into their work, and with ON3P it shows.