At the moment my favourite games are:
Bonanza (it can be brutal and frustrating so be warned)
Book of Dead (there are lots of book game clones but this one is my favourite)
Raging Rex
Captain Venture
Immortal Romance
Halloween Jack
Blood Suckers (the original one)
If I was you I’d try out a few in free mode to get a feel for the games to see what kind of games you like. There are so many to choose from it can be overwhelming when you first start but I found this site to be invaluable for tips on what to try so I’m sure you’ll fine something to your liking
I was also going to suggest blood suckers if you don't mind the older slots. It's a medium variance, maybe even low-medium variance slot with a small house edge. In other words, it has a good chance of giving you some play time and maybe coming out ahead, but won't give you the monster hits of some of the other slots.
Immortal romance is another good slot and a favorite of many people for a reason, medium variance but if you're really lucky there are a few monster wins possible. Pretty good sound/graphic design, though not the newest slot.
I'm not as familiar with all the new stuff, so if the most modern, impressive graphics are important to you, maybe others could point you in the right direction.
I would recommend to start with very small bets until you have a good understanding of how slots work. Probably divide the amount of money you want to risk by about 500 and aim to bet that much on each spin. For example, if you are risking $100, try 20c bets - you can always increase it later. Even low to medium variance slots can take money fast if you're having an unlucky day. You may prefer to be more aggressive with your bet sizing later on, but smarting small is safest - if you start too big, you can't correct the mistake because you'll be out of money. I would consider your first deposit a trial run, and you can decide if you want to take bigger risks after you know what you're getting into. Expect to lose, but be happy if you win.
Once you know what you're doing, I would recommend playing low variance slots on a bigger bet, but keeping a small bet size for the crazy, high variance stuff.
You can try some of the higher variance slots recommended by others, just remember that your money can disappear real fast - so either be prepared for that or again keep the bet sizes low. Dead or alive and bonanza which have been mentioned fits in this category. I don't think I'd recommend dead or alive to start with, it might seem really boring if you don't understand the slot (the appeal comes from the potential in the bonus round). But it is a good game.
The advice mentioned above to consider trying slots in play money first is also worth considering. You could even try out a bunch of slots before you get your paycheck so you know what to expect when you play.
Almost forgot to mention, but you said you were a card and poker player - you could also consider trying out video poker if that's your thing. If you're not familiar with it, it's basically a cross between poker and a slot game. You play directly against the casino and get a payout based on the strength of your hand - stronger hand, bigger payout. Usually 5 card draw.