Every team has different class demands. Aside from the Cleric class, I would say Shaman, Bard, Berserker are usually in high demand or sought after. However, with the above said, I'd recommend playing a class you enjoy first. From there, pursue a team that fits your play style and desires. Later, Furro Leader of Freelance - Open Raid Team - CT Server
Shaman, bard definitely are some I've seen posted often (and what I know I'd love more of here). But it really is guild dependent and sometimes server dependent, so as Furro mentions, the great advice of playing a class you'll enjoy is more rewarding than playing a class that's needed.
I am trying to choose between pally and cleric...feel i might enjoy the pally more but i know cleric Would be easy to find a raid slot.
I have always been very interested in playing a Bard, but for some reason I got the impression that they weren't in demand anymore.
Can always do a paleric or cleridan Cleric is going to be primarily healing (but the role is more varied than it used to be) but then in groups if someone has a healing merc out, you can be a puller or provide a little CC or baby DPS. (Note, dps merc will be better, but it still offers you options). Solo, you can heal a tank/wizard merc or tank yourself on older content. Sometimes I just have go bash out my frustrations and I used to test myself on soloing old raid named. Haven't gotten back into that in a while myself. eqclerics.org site is down but there is some info on there (once/if I can get it back up) to offer suggestions, ideas, etc.